Index: trip-planner-front/node_modules/yargs-parser/build/index.cjs
===================================================================
--- trip-planner-front/node_modules/yargs-parser/build/index.cjs	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
+++ trip-planner-front/node_modules/yargs-parser/build/index.cjs	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
@@ -0,0 +1,1042 @@
+'use strict';
+
+var util = require('util');
+var fs = require('fs');
+var path = require('path');
+
+function camelCase(str) {
+    const isCamelCase = str !== str.toLowerCase() && str !== str.toUpperCase();
+    if (!isCamelCase) {
+        str = str.toLowerCase();
+    }
+    if (str.indexOf('-') === -1 && str.indexOf('_') === -1) {
+        return str;
+    }
+    else {
+        let camelcase = '';
+        let nextChrUpper = false;
+        const leadingHyphens = str.match(/^-+/);
+        for (let i = leadingHyphens ? leadingHyphens[0].length : 0; i < str.length; i++) {
+            let chr = str.charAt(i);
+            if (nextChrUpper) {
+                nextChrUpper = false;
+                chr = chr.toUpperCase();
+            }
+            if (i !== 0 && (chr === '-' || chr === '_')) {
+                nextChrUpper = true;
+            }
+            else if (chr !== '-' && chr !== '_') {
+                camelcase += chr;
+            }
+        }
+        return camelcase;
+    }
+}
+function decamelize(str, joinString) {
+    const lowercase = str.toLowerCase();
+    joinString = joinString || '-';
+    let notCamelcase = '';
+    for (let i = 0; i < str.length; i++) {
+        const chrLower = lowercase.charAt(i);
+        const chrString = str.charAt(i);
+        if (chrLower !== chrString && i > 0) {
+            notCamelcase += `${joinString}${lowercase.charAt(i)}`;
+        }
+        else {
+            notCamelcase += chrString;
+        }
+    }
+    return notCamelcase;
+}
+function looksLikeNumber(x) {
+    if (x === null || x === undefined)
+        return false;
+    if (typeof x === 'number')
+        return true;
+    if (/^0x[0-9a-f]+$/i.test(x))
+        return true;
+    if (/^0[^.]/.test(x))
+        return false;
+    return /^[-]?(?:\d+(?:\.\d*)?|\.\d+)(e[-+]?\d+)?$/.test(x);
+}
+
+function tokenizeArgString(argString) {
+    if (Array.isArray(argString)) {
+        return argString.map(e => typeof e !== 'string' ? e + '' : e);
+    }
+    argString = argString.trim();
+    let i = 0;
+    let prevC = null;
+    let c = null;
+    let opening = null;
+    const args = [];
+    for (let ii = 0; ii < argString.length; ii++) {
+        prevC = c;
+        c = argString.charAt(ii);
+        if (c === ' ' && !opening) {
+            if (!(prevC === ' ')) {
+                i++;
+            }
+            continue;
+        }
+        if (c === opening) {
+            opening = null;
+        }
+        else if ((c === "'" || c === '"') && !opening) {
+            opening = c;
+        }
+        if (!args[i])
+            args[i] = '';
+        args[i] += c;
+    }
+    return args;
+}
+
+var DefaultValuesForTypeKey;
+(function (DefaultValuesForTypeKey) {
+    DefaultValuesForTypeKey["BOOLEAN"] = "boolean";
+    DefaultValuesForTypeKey["STRING"] = "string";
+    DefaultValuesForTypeKey["NUMBER"] = "number";
+    DefaultValuesForTypeKey["ARRAY"] = "array";
+})(DefaultValuesForTypeKey || (DefaultValuesForTypeKey = {}));
+
+let mixin;
+class YargsParser {
+    constructor(_mixin) {
+        mixin = _mixin;
+    }
+    parse(argsInput, options) {
+        const opts = Object.assign({
+            alias: undefined,
+            array: undefined,
+            boolean: undefined,
+            config: undefined,
+            configObjects: undefined,
+            configuration: undefined,
+            coerce: undefined,
+            count: undefined,
+            default: undefined,
+            envPrefix: undefined,
+            narg: undefined,
+            normalize: undefined,
+            string: undefined,
+            number: undefined,
+            __: undefined,
+            key: undefined
+        }, options);
+        const args = tokenizeArgString(argsInput);
+        const aliases = combineAliases(Object.assign(Object.create(null), opts.alias));
+        const configuration = Object.assign({
+            'boolean-negation': true,
+            'camel-case-expansion': true,
+            'combine-arrays': false,
+            'dot-notation': true,
+            'duplicate-arguments-array': true,
+            'flatten-duplicate-arrays': true,
+            'greedy-arrays': true,
+            'halt-at-non-option': false,
+            'nargs-eats-options': false,
+            'negation-prefix': 'no-',
+            'parse-numbers': true,
+            'parse-positional-numbers': true,
+            'populate--': false,
+            'set-placeholder-key': false,
+            'short-option-groups': true,
+            'strip-aliased': false,
+            'strip-dashed': false,
+            'unknown-options-as-args': false
+        }, opts.configuration);
+        const defaults = Object.assign(Object.create(null), opts.default);
+        const configObjects = opts.configObjects || [];
+        const envPrefix = opts.envPrefix;
+        const notFlagsOption = configuration['populate--'];
+        const notFlagsArgv = notFlagsOption ? '--' : '_';
+        const newAliases = Object.create(null);
+        const defaulted = Object.create(null);
+        const __ = opts.__ || mixin.format;
+        const flags = {
+            aliases: Object.create(null),
+            arrays: Object.create(null),
+            bools: Object.create(null),
+            strings: Object.create(null),
+            numbers: Object.create(null),
+            counts: Object.create(null),
+            normalize: Object.create(null),
+            configs: Object.create(null),
+            nargs: Object.create(null),
+            coercions: Object.create(null),
+            keys: []
+        };
+        const negative = /^-([0-9]+(\.[0-9]+)?|\.[0-9]+)$/;
+        const negatedBoolean = new RegExp('^--' + configuration['negation-prefix'] + '(.+)');
+        [].concat(opts.array || []).filter(Boolean).forEach(function (opt) {
+            const key = typeof opt === 'object' ? opt.key : opt;
+            const assignment = Object.keys(opt).map(function (key) {
+                const arrayFlagKeys = {
+                    boolean: 'bools',
+                    string: 'strings',
+                    number: 'numbers'
+                };
+                return arrayFlagKeys[key];
+            }).filter(Boolean).pop();
+            if (assignment) {
+                flags[assignment][key] = true;
+            }
+            flags.arrays[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.boolean || []).filter(Boolean).forEach(function (key) {
+            flags.bools[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.string || []).filter(Boolean).forEach(function (key) {
+            flags.strings[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.number || []).filter(Boolean).forEach(function (key) {
+            flags.numbers[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.count || []).filter(Boolean).forEach(function (key) {
+            flags.counts[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.normalize || []).filter(Boolean).forEach(function (key) {
+            flags.normalize[key] = true;
+            flags.keys.push(key);
+        });
+        if (typeof opts.narg === 'object') {
+            Object.entries(opts.narg).forEach(([key, value]) => {
+                if (typeof value === 'number') {
+                    flags.nargs[key] = value;
+                    flags.keys.push(key);
+                }
+            });
+        }
+        if (typeof opts.coerce === 'object') {
+            Object.entries(opts.coerce).forEach(([key, value]) => {
+                if (typeof value === 'function') {
+                    flags.coercions[key] = value;
+                    flags.keys.push(key);
+                }
+            });
+        }
+        if (typeof opts.config !== 'undefined') {
+            if (Array.isArray(opts.config) || typeof opts.config === 'string') {
+                [].concat(opts.config).filter(Boolean).forEach(function (key) {
+                    flags.configs[key] = true;
+                });
+            }
+            else if (typeof opts.config === 'object') {
+                Object.entries(opts.config).forEach(([key, value]) => {
+                    if (typeof value === 'boolean' || typeof value === 'function') {
+                        flags.configs[key] = value;
+                    }
+                });
+            }
+        }
+        extendAliases(opts.key, aliases, opts.default, flags.arrays);
+        Object.keys(defaults).forEach(function (key) {
+            (flags.aliases[key] || []).forEach(function (alias) {
+                defaults[alias] = defaults[key];
+            });
+        });
+        let error = null;
+        checkConfiguration();
+        let notFlags = [];
+        const argv = Object.assign(Object.create(null), { _: [] });
+        const argvReturn = {};
+        for (let i = 0; i < args.length; i++) {
+            const arg = args[i];
+            const truncatedArg = arg.replace(/^-{3,}/, '---');
+            let broken;
+            let key;
+            let letters;
+            let m;
+            let next;
+            let value;
+            if (arg !== '--' && isUnknownOptionAsArg(arg)) {
+                pushPositional(arg);
+            }
+            else if (truncatedArg.match(/---+(=|$)/)) {
+                pushPositional(arg);
+                continue;
+            }
+            else if (arg.match(/^--.+=/) || (!configuration['short-option-groups'] && arg.match(/^-.+=/))) {
+                m = arg.match(/^--?([^=]+)=([\s\S]*)$/);
+                if (m !== null && Array.isArray(m) && m.length >= 3) {
+                    if (checkAllAliases(m[1], flags.arrays)) {
+                        i = eatArray(i, m[1], args, m[2]);
+                    }
+                    else if (checkAllAliases(m[1], flags.nargs) !== false) {
+                        i = eatNargs(i, m[1], args, m[2]);
+                    }
+                    else {
+                        setArg(m[1], m[2]);
+                    }
+                }
+            }
+            else if (arg.match(negatedBoolean) && configuration['boolean-negation']) {
+                m = arg.match(negatedBoolean);
+                if (m !== null && Array.isArray(m) && m.length >= 2) {
+                    key = m[1];
+                    setArg(key, checkAllAliases(key, flags.arrays) ? [false] : false);
+                }
+            }
+            else if (arg.match(/^--.+/) || (!configuration['short-option-groups'] && arg.match(/^-[^-]+/))) {
+                m = arg.match(/^--?(.+)/);
+                if (m !== null && Array.isArray(m) && m.length >= 2) {
+                    key = m[1];
+                    if (checkAllAliases(key, flags.arrays)) {
+                        i = eatArray(i, key, args);
+                    }
+                    else if (checkAllAliases(key, flags.nargs) !== false) {
+                        i = eatNargs(i, key, args);
+                    }
+                    else {
+                        next = args[i + 1];
+                        if (next !== undefined && (!next.match(/^-/) ||
+                            next.match(negative)) &&
+                            !checkAllAliases(key, flags.bools) &&
+                            !checkAllAliases(key, flags.counts)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else if (/^(true|false)$/.test(next)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else {
+                            setArg(key, defaultValue(key));
+                        }
+                    }
+                }
+            }
+            else if (arg.match(/^-.\..+=/)) {
+                m = arg.match(/^-([^=]+)=([\s\S]*)$/);
+                if (m !== null && Array.isArray(m) && m.length >= 3) {
+                    setArg(m[1], m[2]);
+                }
+            }
+            else if (arg.match(/^-.\..+/) && !arg.match(negative)) {
+                next = args[i + 1];
+                m = arg.match(/^-(.\..+)/);
+                if (m !== null && Array.isArray(m) && m.length >= 2) {
+                    key = m[1];
+                    if (next !== undefined && !next.match(/^-/) &&
+                        !checkAllAliases(key, flags.bools) &&
+                        !checkAllAliases(key, flags.counts)) {
+                        setArg(key, next);
+                        i++;
+                    }
+                    else {
+                        setArg(key, defaultValue(key));
+                    }
+                }
+            }
+            else if (arg.match(/^-[^-]+/) && !arg.match(negative)) {
+                letters = arg.slice(1, -1).split('');
+                broken = false;
+                for (let j = 0; j < letters.length; j++) {
+                    next = arg.slice(j + 2);
+                    if (letters[j + 1] && letters[j + 1] === '=') {
+                        value = arg.slice(j + 3);
+                        key = letters[j];
+                        if (checkAllAliases(key, flags.arrays)) {
+                            i = eatArray(i, key, args, value);
+                        }
+                        else if (checkAllAliases(key, flags.nargs) !== false) {
+                            i = eatNargs(i, key, args, value);
+                        }
+                        else {
+                            setArg(key, value);
+                        }
+                        broken = true;
+                        break;
+                    }
+                    if (next === '-') {
+                        setArg(letters[j], next);
+                        continue;
+                    }
+                    if (/[A-Za-z]/.test(letters[j]) &&
+                        /^-?\d+(\.\d*)?(e-?\d+)?$/.test(next) &&
+                        checkAllAliases(next, flags.bools) === false) {
+                        setArg(letters[j], next);
+                        broken = true;
+                        break;
+                    }
+                    if (letters[j + 1] && letters[j + 1].match(/\W/)) {
+                        setArg(letters[j], next);
+                        broken = true;
+                        break;
+                    }
+                    else {
+                        setArg(letters[j], defaultValue(letters[j]));
+                    }
+                }
+                key = arg.slice(-1)[0];
+                if (!broken && key !== '-') {
+                    if (checkAllAliases(key, flags.arrays)) {
+                        i = eatArray(i, key, args);
+                    }
+                    else if (checkAllAliases(key, flags.nargs) !== false) {
+                        i = eatNargs(i, key, args);
+                    }
+                    else {
+                        next = args[i + 1];
+                        if (next !== undefined && (!/^(-|--)[^-]/.test(next) ||
+                            next.match(negative)) &&
+                            !checkAllAliases(key, flags.bools) &&
+                            !checkAllAliases(key, flags.counts)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else if (/^(true|false)$/.test(next)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else {
+                            setArg(key, defaultValue(key));
+                        }
+                    }
+                }
+            }
+            else if (arg.match(/^-[0-9]$/) &&
+                arg.match(negative) &&
+                checkAllAliases(arg.slice(1), flags.bools)) {
+                key = arg.slice(1);
+                setArg(key, defaultValue(key));
+            }
+            else if (arg === '--') {
+                notFlags = args.slice(i + 1);
+                break;
+            }
+            else if (configuration['halt-at-non-option']) {
+                notFlags = args.slice(i);
+                break;
+            }
+            else {
+                pushPositional(arg);
+            }
+        }
+        applyEnvVars(argv, true);
+        applyEnvVars(argv, false);
+        setConfig(argv);
+        setConfigObjects();
+        applyDefaultsAndAliases(argv, flags.aliases, defaults, true);
+        applyCoercions(argv);
+        if (configuration['set-placeholder-key'])
+            setPlaceholderKeys(argv);
+        Object.keys(flags.counts).forEach(function (key) {
+            if (!hasKey(argv, key.split('.')))
+                setArg(key, 0);
+        });
+        if (notFlagsOption && notFlags.length)
+            argv[notFlagsArgv] = [];
+        notFlags.forEach(function (key) {
+            argv[notFlagsArgv].push(key);
+        });
+        if (configuration['camel-case-expansion'] && configuration['strip-dashed']) {
+            Object.keys(argv).filter(key => key !== '--' && key.includes('-')).forEach(key => {
+                delete argv[key];
+            });
+        }
+        if (configuration['strip-aliased']) {
+            [].concat(...Object.keys(aliases).map(k => aliases[k])).forEach(alias => {
+                if (configuration['camel-case-expansion'] && alias.includes('-')) {
+                    delete argv[alias.split('.').map(prop => camelCase(prop)).join('.')];
+                }
+                delete argv[alias];
+            });
+        }
+        function pushPositional(arg) {
+            const maybeCoercedNumber = maybeCoerceNumber('_', arg);
+            if (typeof maybeCoercedNumber === 'string' || typeof maybeCoercedNumber === 'number') {
+                argv._.push(maybeCoercedNumber);
+            }
+        }
+        function eatNargs(i, key, args, argAfterEqualSign) {
+            let ii;
+            let toEat = checkAllAliases(key, flags.nargs);
+            toEat = typeof toEat !== 'number' || isNaN(toEat) ? 1 : toEat;
+            if (toEat === 0) {
+                if (!isUndefined(argAfterEqualSign)) {
+                    error = Error(__('Argument unexpected for: %s', key));
+                }
+                setArg(key, defaultValue(key));
+                return i;
+            }
+            let available = isUndefined(argAfterEqualSign) ? 0 : 1;
+            if (configuration['nargs-eats-options']) {
+                if (args.length - (i + 1) + available < toEat) {
+                    error = Error(__('Not enough arguments following: %s', key));
+                }
+                available = toEat;
+            }
+            else {
+                for (ii = i + 1; ii < args.length; ii++) {
+                    if (!args[ii].match(/^-[^0-9]/) || args[ii].match(negative) || isUnknownOptionAsArg(args[ii]))
+                        available++;
+                    else
+                        break;
+                }
+                if (available < toEat)
+                    error = Error(__('Not enough arguments following: %s', key));
+            }
+            let consumed = Math.min(available, toEat);
+            if (!isUndefined(argAfterEqualSign) && consumed > 0) {
+                setArg(key, argAfterEqualSign);
+                consumed--;
+            }
+            for (ii = i + 1; ii < (consumed + i + 1); ii++) {
+                setArg(key, args[ii]);
+            }
+            return (i + consumed);
+        }
+        function eatArray(i, key, args, argAfterEqualSign) {
+            let argsToSet = [];
+            let next = argAfterEqualSign || args[i + 1];
+            const nargsCount = checkAllAliases(key, flags.nargs);
+            if (checkAllAliases(key, flags.bools) && !(/^(true|false)$/.test(next))) {
+                argsToSet.push(true);
+            }
+            else if (isUndefined(next) ||
+                (isUndefined(argAfterEqualSign) && /^-/.test(next) && !negative.test(next) && !isUnknownOptionAsArg(next))) {
+                if (defaults[key] !== undefined) {
+                    const defVal = defaults[key];
+                    argsToSet = Array.isArray(defVal) ? defVal : [defVal];
+                }
+            }
+            else {
+                if (!isUndefined(argAfterEqualSign)) {
+                    argsToSet.push(processValue(key, argAfterEqualSign));
+                }
+                for (let ii = i + 1; ii < args.length; ii++) {
+                    if ((!configuration['greedy-arrays'] && argsToSet.length > 0) ||
+                        (nargsCount && typeof nargsCount === 'number' && argsToSet.length >= nargsCount))
+                        break;
+                    next = args[ii];
+                    if (/^-/.test(next) && !negative.test(next) && !isUnknownOptionAsArg(next))
+                        break;
+                    i = ii;
+                    argsToSet.push(processValue(key, next));
+                }
+            }
+            if (typeof nargsCount === 'number' && ((nargsCount && argsToSet.length < nargsCount) ||
+                (isNaN(nargsCount) && argsToSet.length === 0))) {
+                error = Error(__('Not enough arguments following: %s', key));
+            }
+            setArg(key, argsToSet);
+            return i;
+        }
+        function setArg(key, val) {
+            if (/-/.test(key) && configuration['camel-case-expansion']) {
+                const alias = key.split('.').map(function (prop) {
+                    return camelCase(prop);
+                }).join('.');
+                addNewAlias(key, alias);
+            }
+            const value = processValue(key, val);
+            const splitKey = key.split('.');
+            setKey(argv, splitKey, value);
+            if (flags.aliases[key]) {
+                flags.aliases[key].forEach(function (x) {
+                    const keyProperties = x.split('.');
+                    setKey(argv, keyProperties, value);
+                });
+            }
+            if (splitKey.length > 1 && configuration['dot-notation']) {
+                (flags.aliases[splitKey[0]] || []).forEach(function (x) {
+                    let keyProperties = x.split('.');
+                    const a = [].concat(splitKey);
+                    a.shift();
+                    keyProperties = keyProperties.concat(a);
+                    if (!(flags.aliases[key] || []).includes(keyProperties.join('.'))) {
+                        setKey(argv, keyProperties, value);
+                    }
+                });
+            }
+            if (checkAllAliases(key, flags.normalize) && !checkAllAliases(key, flags.arrays)) {
+                const keys = [key].concat(flags.aliases[key] || []);
+                keys.forEach(function (key) {
+                    Object.defineProperty(argvReturn, key, {
+                        enumerable: true,
+                        get() {
+                            return val;
+                        },
+                        set(value) {
+                            val = typeof value === 'string' ? mixin.normalize(value) : value;
+                        }
+                    });
+                });
+            }
+        }
+        function addNewAlias(key, alias) {
+            if (!(flags.aliases[key] && flags.aliases[key].length)) {
+                flags.aliases[key] = [alias];
+                newAliases[alias] = true;
+            }
+            if (!(flags.aliases[alias] && flags.aliases[alias].length)) {
+                addNewAlias(alias, key);
+            }
+        }
+        function processValue(key, val) {
+            if (typeof val === 'string' &&
+                (val[0] === "'" || val[0] === '"') &&
+                val[val.length - 1] === val[0]) {
+                val = val.substring(1, val.length - 1);
+            }
+            if (checkAllAliases(key, flags.bools) || checkAllAliases(key, flags.counts)) {
+                if (typeof val === 'string')
+                    val = val === 'true';
+            }
+            let value = Array.isArray(val)
+                ? val.map(function (v) { return maybeCoerceNumber(key, v); })
+                : maybeCoerceNumber(key, val);
+            if (checkAllAliases(key, flags.counts) && (isUndefined(value) || typeof value === 'boolean')) {
+                value = increment();
+            }
+            if (checkAllAliases(key, flags.normalize) && checkAllAliases(key, flags.arrays)) {
+                if (Array.isArray(val))
+                    value = val.map((val) => { return mixin.normalize(val); });
+                else
+                    value = mixin.normalize(val);
+            }
+            return value;
+        }
+        function maybeCoerceNumber(key, value) {
+            if (!configuration['parse-positional-numbers'] && key === '_')
+                return value;
+            if (!checkAllAliases(key, flags.strings) && !checkAllAliases(key, flags.bools) && !Array.isArray(value)) {
+                const shouldCoerceNumber = looksLikeNumber(value) && configuration['parse-numbers'] && (Number.isSafeInteger(Math.floor(parseFloat(`${value}`))));
+                if (shouldCoerceNumber || (!isUndefined(value) && checkAllAliases(key, flags.numbers))) {
+                    value = Number(value);
+                }
+            }
+            return value;
+        }
+        function setConfig(argv) {
+            const configLookup = Object.create(null);
+            applyDefaultsAndAliases(configLookup, flags.aliases, defaults);
+            Object.keys(flags.configs).forEach(function (configKey) {
+                const configPath = argv[configKey] || configLookup[configKey];
+                if (configPath) {
+                    try {
+                        let config = null;
+                        const resolvedConfigPath = mixin.resolve(mixin.cwd(), configPath);
+                        const resolveConfig = flags.configs[configKey];
+                        if (typeof resolveConfig === 'function') {
+                            try {
+                                config = resolveConfig(resolvedConfigPath);
+                            }
+                            catch (e) {
+                                config = e;
+                            }
+                            if (config instanceof Error) {
+                                error = config;
+                                return;
+                            }
+                        }
+                        else {
+                            config = mixin.require(resolvedConfigPath);
+                        }
+                        setConfigObject(config);
+                    }
+                    catch (ex) {
+                        if (ex.name === 'PermissionDenied')
+                            error = ex;
+                        else if (argv[configKey])
+                            error = Error(__('Invalid JSON config file: %s', configPath));
+                    }
+                }
+            });
+        }
+        function setConfigObject(config, prev) {
+            Object.keys(config).forEach(function (key) {
+                const value = config[key];
+                const fullKey = prev ? prev + '.' + key : key;
+                if (typeof value === 'object' && value !== null && !Array.isArray(value) && configuration['dot-notation']) {
+                    setConfigObject(value, fullKey);
+                }
+                else {
+                    if (!hasKey(argv, fullKey.split('.')) || (checkAllAliases(fullKey, flags.arrays) && configuration['combine-arrays'])) {
+                        setArg(fullKey, value);
+                    }
+                }
+            });
+        }
+        function setConfigObjects() {
+            if (typeof configObjects !== 'undefined') {
+                configObjects.forEach(function (configObject) {
+                    setConfigObject(configObject);
+                });
+            }
+        }
+        function applyEnvVars(argv, configOnly) {
+            if (typeof envPrefix === 'undefined')
+                return;
+            const prefix = typeof envPrefix === 'string' ? envPrefix : '';
+            const env = mixin.env();
+            Object.keys(env).forEach(function (envVar) {
+                if (prefix === '' || envVar.lastIndexOf(prefix, 0) === 0) {
+                    const keys = envVar.split('__').map(function (key, i) {
+                        if (i === 0) {
+                            key = key.substring(prefix.length);
+                        }
+                        return camelCase(key);
+                    });
+                    if (((configOnly && flags.configs[keys.join('.')]) || !configOnly) && !hasKey(argv, keys)) {
+                        setArg(keys.join('.'), env[envVar]);
+                    }
+                }
+            });
+        }
+        function applyCoercions(argv) {
+            let coerce;
+            const applied = new Set();
+            Object.keys(argv).forEach(function (key) {
+                if (!applied.has(key)) {
+                    coerce = checkAllAliases(key, flags.coercions);
+                    if (typeof coerce === 'function') {
+                        try {
+                            const value = maybeCoerceNumber(key, coerce(argv[key]));
+                            ([].concat(flags.aliases[key] || [], key)).forEach(ali => {
+                                applied.add(ali);
+                                argv[ali] = value;
+                            });
+                        }
+                        catch (err) {
+                            error = err;
+                        }
+                    }
+                }
+            });
+        }
+        function setPlaceholderKeys(argv) {
+            flags.keys.forEach((key) => {
+                if (~key.indexOf('.'))
+                    return;
+                if (typeof argv[key] === 'undefined')
+                    argv[key] = undefined;
+            });
+            return argv;
+        }
+        function applyDefaultsAndAliases(obj, aliases, defaults, canLog = false) {
+            Object.keys(defaults).forEach(function (key) {
+                if (!hasKey(obj, key.split('.'))) {
+                    setKey(obj, key.split('.'), defaults[key]);
+                    if (canLog)
+                        defaulted[key] = true;
+                    (aliases[key] || []).forEach(function (x) {
+                        if (hasKey(obj, x.split('.')))
+                            return;
+                        setKey(obj, x.split('.'), defaults[key]);
+                    });
+                }
+            });
+        }
+        function hasKey(obj, keys) {
+            let o = obj;
+            if (!configuration['dot-notation'])
+                keys = [keys.join('.')];
+            keys.slice(0, -1).forEach(function (key) {
+                o = (o[key] || {});
+            });
+            const key = keys[keys.length - 1];
+            if (typeof o !== 'object')
+                return false;
+            else
+                return key in o;
+        }
+        function setKey(obj, keys, value) {
+            let o = obj;
+            if (!configuration['dot-notation'])
+                keys = [keys.join('.')];
+            keys.slice(0, -1).forEach(function (key) {
+                key = sanitizeKey(key);
+                if (typeof o === 'object' && o[key] === undefined) {
+                    o[key] = {};
+                }
+                if (typeof o[key] !== 'object' || Array.isArray(o[key])) {
+                    if (Array.isArray(o[key])) {
+                        o[key].push({});
+                    }
+                    else {
+                        o[key] = [o[key], {}];
+                    }
+                    o = o[key][o[key].length - 1];
+                }
+                else {
+                    o = o[key];
+                }
+            });
+            const key = sanitizeKey(keys[keys.length - 1]);
+            const isTypeArray = checkAllAliases(keys.join('.'), flags.arrays);
+            const isValueArray = Array.isArray(value);
+            let duplicate = configuration['duplicate-arguments-array'];
+            if (!duplicate && checkAllAliases(key, flags.nargs)) {
+                duplicate = true;
+                if ((!isUndefined(o[key]) && flags.nargs[key] === 1) || (Array.isArray(o[key]) && o[key].length === flags.nargs[key])) {
+                    o[key] = undefined;
+                }
+            }
+            if (value === increment()) {
+                o[key] = increment(o[key]);
+            }
+            else if (Array.isArray(o[key])) {
+                if (duplicate && isTypeArray && isValueArray) {
+                    o[key] = configuration['flatten-duplicate-arrays'] ? o[key].concat(value) : (Array.isArray(o[key][0]) ? o[key] : [o[key]]).concat([value]);
+                }
+                else if (!duplicate && Boolean(isTypeArray) === Boolean(isValueArray)) {
+                    o[key] = value;
+                }
+                else {
+                    o[key] = o[key].concat([value]);
+                }
+            }
+            else if (o[key] === undefined && isTypeArray) {
+                o[key] = isValueArray ? value : [value];
+            }
+            else if (duplicate && !(o[key] === undefined ||
+                checkAllAliases(key, flags.counts) ||
+                checkAllAliases(key, flags.bools))) {
+                o[key] = [o[key], value];
+            }
+            else {
+                o[key] = value;
+            }
+        }
+        function extendAliases(...args) {
+            args.forEach(function (obj) {
+                Object.keys(obj || {}).forEach(function (key) {
+                    if (flags.aliases[key])
+                        return;
+                    flags.aliases[key] = [].concat(aliases[key] || []);
+                    flags.aliases[key].concat(key).forEach(function (x) {
+                        if (/-/.test(x) && configuration['camel-case-expansion']) {
+                            const c = camelCase(x);
+                            if (c !== key && flags.aliases[key].indexOf(c) === -1) {
+                                flags.aliases[key].push(c);
+                                newAliases[c] = true;
+                            }
+                        }
+                    });
+                    flags.aliases[key].concat(key).forEach(function (x) {
+                        if (x.length > 1 && /[A-Z]/.test(x) && configuration['camel-case-expansion']) {
+                            const c = decamelize(x, '-');
+                            if (c !== key && flags.aliases[key].indexOf(c) === -1) {
+                                flags.aliases[key].push(c);
+                                newAliases[c] = true;
+                            }
+                        }
+                    });
+                    flags.aliases[key].forEach(function (x) {
+                        flags.aliases[x] = [key].concat(flags.aliases[key].filter(function (y) {
+                            return x !== y;
+                        }));
+                    });
+                });
+            });
+        }
+        function checkAllAliases(key, flag) {
+            const toCheck = [].concat(flags.aliases[key] || [], key);
+            const keys = Object.keys(flag);
+            const setAlias = toCheck.find(key => keys.includes(key));
+            return setAlias ? flag[setAlias] : false;
+        }
+        function hasAnyFlag(key) {
+            const flagsKeys = Object.keys(flags);
+            const toCheck = [].concat(flagsKeys.map(k => flags[k]));
+            return toCheck.some(function (flag) {
+                return Array.isArray(flag) ? flag.includes(key) : flag[key];
+            });
+        }
+        function hasFlagsMatching(arg, ...patterns) {
+            const toCheck = [].concat(...patterns);
+            return toCheck.some(function (pattern) {
+                const match = arg.match(pattern);
+                return match && hasAnyFlag(match[1]);
+            });
+        }
+        function hasAllShortFlags(arg) {
+            if (arg.match(negative) || !arg.match(/^-[^-]+/)) {
+                return false;
+            }
+            let hasAllFlags = true;
+            let next;
+            const letters = arg.slice(1).split('');
+            for (let j = 0; j < letters.length; j++) {
+                next = arg.slice(j + 2);
+                if (!hasAnyFlag(letters[j])) {
+                    hasAllFlags = false;
+                    break;
+                }
+                if ((letters[j + 1] && letters[j + 1] === '=') ||
+                    next === '-' ||
+                    (/[A-Za-z]/.test(letters[j]) && /^-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) ||
+                    (letters[j + 1] && letters[j + 1].match(/\W/))) {
+                    break;
+                }
+            }
+            return hasAllFlags;
+        }
+        function isUnknownOptionAsArg(arg) {
+            return configuration['unknown-options-as-args'] && isUnknownOption(arg);
+        }
+        function isUnknownOption(arg) {
+            arg = arg.replace(/^-{3,}/, '--');
+            if (arg.match(negative)) {
+                return false;
+            }
+            if (hasAllShortFlags(arg)) {
+                return false;
+            }
+            const flagWithEquals = /^-+([^=]+?)=[\s\S]*$/;
+            const normalFlag = /^-+([^=]+?)$/;
+            const flagEndingInHyphen = /^-+([^=]+?)-$/;
+            const flagEndingInDigits = /^-+([^=]+?\d+)$/;
+            const flagEndingInNonWordCharacters = /^-+([^=]+?)\W+.*$/;
+            return !hasFlagsMatching(arg, flagWithEquals, negatedBoolean, normalFlag, flagEndingInHyphen, flagEndingInDigits, flagEndingInNonWordCharacters);
+        }
+        function defaultValue(key) {
+            if (!checkAllAliases(key, flags.bools) &&
+                !checkAllAliases(key, flags.counts) &&
+                `${key}` in defaults) {
+                return defaults[key];
+            }
+            else {
+                return defaultForType(guessType(key));
+            }
+        }
+        function defaultForType(type) {
+            const def = {
+                [DefaultValuesForTypeKey.BOOLEAN]: true,
+                [DefaultValuesForTypeKey.STRING]: '',
+                [DefaultValuesForTypeKey.NUMBER]: undefined,
+                [DefaultValuesForTypeKey.ARRAY]: []
+            };
+            return def[type];
+        }
+        function guessType(key) {
+            let type = DefaultValuesForTypeKey.BOOLEAN;
+            if (checkAllAliases(key, flags.strings))
+                type = DefaultValuesForTypeKey.STRING;
+            else if (checkAllAliases(key, flags.numbers))
+                type = DefaultValuesForTypeKey.NUMBER;
+            else if (checkAllAliases(key, flags.bools))
+                type = DefaultValuesForTypeKey.BOOLEAN;
+            else if (checkAllAliases(key, flags.arrays))
+                type = DefaultValuesForTypeKey.ARRAY;
+            return type;
+        }
+        function isUndefined(num) {
+            return num === undefined;
+        }
+        function checkConfiguration() {
+            Object.keys(flags.counts).find(key => {
+                if (checkAllAliases(key, flags.arrays)) {
+                    error = Error(__('Invalid configuration: %s, opts.count excludes opts.array.', key));
+                    return true;
+                }
+                else if (checkAllAliases(key, flags.nargs)) {
+                    error = Error(__('Invalid configuration: %s, opts.count excludes opts.narg.', key));
+                    return true;
+                }
+                return false;
+            });
+        }
+        return {
+            aliases: Object.assign({}, flags.aliases),
+            argv: Object.assign(argvReturn, argv),
+            configuration: configuration,
+            defaulted: Object.assign({}, defaulted),
+            error: error,
+            newAliases: Object.assign({}, newAliases)
+        };
+    }
+}
+function combineAliases(aliases) {
+    const aliasArrays = [];
+    const combined = Object.create(null);
+    let change = true;
+    Object.keys(aliases).forEach(function (key) {
+        aliasArrays.push([].concat(aliases[key], key));
+    });
+    while (change) {
+        change = false;
+        for (let i = 0; i < aliasArrays.length; i++) {
+            for (let ii = i + 1; ii < aliasArrays.length; ii++) {
+                const intersect = aliasArrays[i].filter(function (v) {
+                    return aliasArrays[ii].indexOf(v) !== -1;
+                });
+                if (intersect.length) {
+                    aliasArrays[i] = aliasArrays[i].concat(aliasArrays[ii]);
+                    aliasArrays.splice(ii, 1);
+                    change = true;
+                    break;
+                }
+            }
+        }
+    }
+    aliasArrays.forEach(function (aliasArray) {
+        aliasArray = aliasArray.filter(function (v, i, self) {
+            return self.indexOf(v) === i;
+        });
+        const lastAlias = aliasArray.pop();
+        if (lastAlias !== undefined && typeof lastAlias === 'string') {
+            combined[lastAlias] = aliasArray;
+        }
+    });
+    return combined;
+}
+function increment(orig) {
+    return orig !== undefined ? orig + 1 : 1;
+}
+function sanitizeKey(key) {
+    if (key === '__proto__')
+        return '___proto___';
+    return key;
+}
+
+const minNodeVersion = (process && process.env && process.env.YARGS_MIN_NODE_VERSION)
+    ? Number(process.env.YARGS_MIN_NODE_VERSION)
+    : 10;
+if (process && process.version) {
+    const major = Number(process.version.match(/v([^.]+)/)[1]);
+    if (major < minNodeVersion) {
+        throw Error(`yargs parser supports a minimum Node.js version of ${minNodeVersion}. Read our version support policy: https://github.com/yargs/yargs-parser#supported-nodejs-versions`);
+    }
+}
+const env = process ? process.env : {};
+const parser = new YargsParser({
+    cwd: process.cwd,
+    env: () => {
+        return env;
+    },
+    format: util.format,
+    normalize: path.normalize,
+    resolve: path.resolve,
+    require: (path) => {
+        if (typeof require !== 'undefined') {
+            return require(path);
+        }
+        else if (path.match(/\.json$/)) {
+            return fs.readFileSync(path, 'utf8');
+        }
+        else {
+            throw Error('only .json config files are supported in ESM');
+        }
+    }
+});
+const yargsParser = function Parser(args, opts) {
+    const result = parser.parse(args.slice(), opts);
+    return result.argv;
+};
+yargsParser.detailed = function (args, opts) {
+    return parser.parse(args.slice(), opts);
+};
+yargsParser.camelCase = camelCase;
+yargsParser.decamelize = decamelize;
+yargsParser.looksLikeNumber = looksLikeNumber;
+
+module.exports = yargsParser;
Index: trip-planner-front/node_modules/yargs-parser/build/lib/index.js
===================================================================
--- trip-planner-front/node_modules/yargs-parser/build/lib/index.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
+++ trip-planner-front/node_modules/yargs-parser/build/lib/index.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
@@ -0,0 +1,59 @@
+/**
+ * @fileoverview Main entrypoint for libraries using yargs-parser in Node.js
+ * CJS and ESM environments.
+ *
+ * @license
+ * Copyright (c) 2016, Contributors
+ * SPDX-License-Identifier: ISC
+ */
+import { format } from 'util';
+import { readFileSync } from 'fs';
+import { normalize, resolve } from 'path';
+import { camelCase, decamelize, looksLikeNumber } from './string-utils.js';
+import { YargsParser } from './yargs-parser.js';
+// See https://github.com/yargs/yargs-parser#supported-nodejs-versions for our
+// version support policy. The YARGS_MIN_NODE_VERSION is used for testing only.
+const minNodeVersion = (process && process.env && process.env.YARGS_MIN_NODE_VERSION)
+    ? Number(process.env.YARGS_MIN_NODE_VERSION)
+    : 10;
+if (process && process.version) {
+    const major = Number(process.version.match(/v([^.]+)/)[1]);
+    if (major < minNodeVersion) {
+        throw Error(`yargs parser supports a minimum Node.js version of ${minNodeVersion}. Read our version support policy: https://github.com/yargs/yargs-parser#supported-nodejs-versions`);
+    }
+}
+// Creates a yargs-parser instance using Node.js standard libraries:
+const env = process ? process.env : {};
+const parser = new YargsParser({
+    cwd: process.cwd,
+    env: () => {
+        return env;
+    },
+    format,
+    normalize,
+    resolve,
+    // TODO: figure  out a  way to combine ESM and CJS coverage, such  that
+    // we can exercise all the lines below:
+    require: (path) => {
+        if (typeof require !== 'undefined') {
+            return require(path);
+        }
+        else if (path.match(/\.json$/)) {
+            return readFileSync(path, 'utf8');
+        }
+        else {
+            throw Error('only .json config files are supported in ESM');
+        }
+    }
+});
+const yargsParser = function Parser(args, opts) {
+    const result = parser.parse(args.slice(), opts);
+    return result.argv;
+};
+yargsParser.detailed = function (args, opts) {
+    return parser.parse(args.slice(), opts);
+};
+yargsParser.camelCase = camelCase;
+yargsParser.decamelize = decamelize;
+yargsParser.looksLikeNumber = looksLikeNumber;
+export default yargsParser;
Index: trip-planner-front/node_modules/yargs-parser/build/lib/string-utils.js
===================================================================
--- trip-planner-front/node_modules/yargs-parser/build/lib/string-utils.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
+++ trip-planner-front/node_modules/yargs-parser/build/lib/string-utils.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
@@ -0,0 +1,65 @@
+/**
+ * @license
+ * Copyright (c) 2016, Contributors
+ * SPDX-License-Identifier: ISC
+ */
+export function camelCase(str) {
+    // Handle the case where an argument is provided as camel case, e.g., fooBar.
+    // by ensuring that the string isn't already mixed case:
+    const isCamelCase = str !== str.toLowerCase() && str !== str.toUpperCase();
+    if (!isCamelCase) {
+        str = str.toLowerCase();
+    }
+    if (str.indexOf('-') === -1 && str.indexOf('_') === -1) {
+        return str;
+    }
+    else {
+        let camelcase = '';
+        let nextChrUpper = false;
+        const leadingHyphens = str.match(/^-+/);
+        for (let i = leadingHyphens ? leadingHyphens[0].length : 0; i < str.length; i++) {
+            let chr = str.charAt(i);
+            if (nextChrUpper) {
+                nextChrUpper = false;
+                chr = chr.toUpperCase();
+            }
+            if (i !== 0 && (chr === '-' || chr === '_')) {
+                nextChrUpper = true;
+            }
+            else if (chr !== '-' && chr !== '_') {
+                camelcase += chr;
+            }
+        }
+        return camelcase;
+    }
+}
+export function decamelize(str, joinString) {
+    const lowercase = str.toLowerCase();
+    joinString = joinString || '-';
+    let notCamelcase = '';
+    for (let i = 0; i < str.length; i++) {
+        const chrLower = lowercase.charAt(i);
+        const chrString = str.charAt(i);
+        if (chrLower !== chrString && i > 0) {
+            notCamelcase += `${joinString}${lowercase.charAt(i)}`;
+        }
+        else {
+            notCamelcase += chrString;
+        }
+    }
+    return notCamelcase;
+}
+export function looksLikeNumber(x) {
+    if (x === null || x === undefined)
+        return false;
+    // if loaded from config, may already be a number.
+    if (typeof x === 'number')
+        return true;
+    // hexadecimal.
+    if (/^0x[0-9a-f]+$/i.test(x))
+        return true;
+    // don't treat 0123 as a number; as it drops the leading '0'.
+    if (/^0[^.]/.test(x))
+        return false;
+    return /^[-]?(?:\d+(?:\.\d*)?|\.\d+)(e[-+]?\d+)?$/.test(x);
+}
Index: trip-planner-front/node_modules/yargs-parser/build/lib/tokenize-arg-string.js
===================================================================
--- trip-planner-front/node_modules/yargs-parser/build/lib/tokenize-arg-string.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
+++ trip-planner-front/node_modules/yargs-parser/build/lib/tokenize-arg-string.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright (c) 2016, Contributors
+ * SPDX-License-Identifier: ISC
+ */
+// take an un-split argv string and tokenize it.
+export function tokenizeArgString(argString) {
+    if (Array.isArray(argString)) {
+        return argString.map(e => typeof e !== 'string' ? e + '' : e);
+    }
+    argString = argString.trim();
+    let i = 0;
+    let prevC = null;
+    let c = null;
+    let opening = null;
+    const args = [];
+    for (let ii = 0; ii < argString.length; ii++) {
+        prevC = c;
+        c = argString.charAt(ii);
+        // split on spaces unless we're in quotes.
+        if (c === ' ' && !opening) {
+            if (!(prevC === ' ')) {
+                i++;
+            }
+            continue;
+        }
+        // don't split the string if we're in matching
+        // opening or closing single and double quotes.
+        if (c === opening) {
+            opening = null;
+        }
+        else if ((c === "'" || c === '"') && !opening) {
+            opening = c;
+        }
+        if (!args[i])
+            args[i] = '';
+        args[i] += c;
+    }
+    return args;
+}
Index: trip-planner-front/node_modules/yargs-parser/build/lib/yargs-parser-types.js
===================================================================
--- trip-planner-front/node_modules/yargs-parser/build/lib/yargs-parser-types.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
+++ trip-planner-front/node_modules/yargs-parser/build/lib/yargs-parser-types.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
@@ -0,0 +1,12 @@
+/**
+ * @license
+ * Copyright (c) 2016, Contributors
+ * SPDX-License-Identifier: ISC
+ */
+export var DefaultValuesForTypeKey;
+(function (DefaultValuesForTypeKey) {
+    DefaultValuesForTypeKey["BOOLEAN"] = "boolean";
+    DefaultValuesForTypeKey["STRING"] = "string";
+    DefaultValuesForTypeKey["NUMBER"] = "number";
+    DefaultValuesForTypeKey["ARRAY"] = "array";
+})(DefaultValuesForTypeKey || (DefaultValuesForTypeKey = {}));
Index: trip-planner-front/node_modules/yargs-parser/build/lib/yargs-parser.js
===================================================================
--- trip-planner-front/node_modules/yargs-parser/build/lib/yargs-parser.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
+++ trip-planner-front/node_modules/yargs-parser/build/lib/yargs-parser.js	(revision 6a3a178323fd905112b5392bd9d3cb83b66ef2d3)
@@ -0,0 +1,1037 @@
+/**
+ * @license
+ * Copyright (c) 2016, Contributors
+ * SPDX-License-Identifier: ISC
+ */
+import { tokenizeArgString } from './tokenize-arg-string.js';
+import { DefaultValuesForTypeKey } from './yargs-parser-types.js';
+import { camelCase, decamelize, looksLikeNumber } from './string-utils.js';
+let mixin;
+export class YargsParser {
+    constructor(_mixin) {
+        mixin = _mixin;
+    }
+    parse(argsInput, options) {
+        const opts = Object.assign({
+            alias: undefined,
+            array: undefined,
+            boolean: undefined,
+            config: undefined,
+            configObjects: undefined,
+            configuration: undefined,
+            coerce: undefined,
+            count: undefined,
+            default: undefined,
+            envPrefix: undefined,
+            narg: undefined,
+            normalize: undefined,
+            string: undefined,
+            number: undefined,
+            __: undefined,
+            key: undefined
+        }, options);
+        // allow a string argument to be passed in rather
+        // than an argv array.
+        const args = tokenizeArgString(argsInput);
+        // aliases might have transitive relationships, normalize this.
+        const aliases = combineAliases(Object.assign(Object.create(null), opts.alias));
+        const configuration = Object.assign({
+            'boolean-negation': true,
+            'camel-case-expansion': true,
+            'combine-arrays': false,
+            'dot-notation': true,
+            'duplicate-arguments-array': true,
+            'flatten-duplicate-arrays': true,
+            'greedy-arrays': true,
+            'halt-at-non-option': false,
+            'nargs-eats-options': false,
+            'negation-prefix': 'no-',
+            'parse-numbers': true,
+            'parse-positional-numbers': true,
+            'populate--': false,
+            'set-placeholder-key': false,
+            'short-option-groups': true,
+            'strip-aliased': false,
+            'strip-dashed': false,
+            'unknown-options-as-args': false
+        }, opts.configuration);
+        const defaults = Object.assign(Object.create(null), opts.default);
+        const configObjects = opts.configObjects || [];
+        const envPrefix = opts.envPrefix;
+        const notFlagsOption = configuration['populate--'];
+        const notFlagsArgv = notFlagsOption ? '--' : '_';
+        const newAliases = Object.create(null);
+        const defaulted = Object.create(null);
+        // allow a i18n handler to be passed in, default to a fake one (util.format).
+        const __ = opts.__ || mixin.format;
+        const flags = {
+            aliases: Object.create(null),
+            arrays: Object.create(null),
+            bools: Object.create(null),
+            strings: Object.create(null),
+            numbers: Object.create(null),
+            counts: Object.create(null),
+            normalize: Object.create(null),
+            configs: Object.create(null),
+            nargs: Object.create(null),
+            coercions: Object.create(null),
+            keys: []
+        };
+        const negative = /^-([0-9]+(\.[0-9]+)?|\.[0-9]+)$/;
+        const negatedBoolean = new RegExp('^--' + configuration['negation-prefix'] + '(.+)');
+        [].concat(opts.array || []).filter(Boolean).forEach(function (opt) {
+            const key = typeof opt === 'object' ? opt.key : opt;
+            // assign to flags[bools|strings|numbers]
+            const assignment = Object.keys(opt).map(function (key) {
+                const arrayFlagKeys = {
+                    boolean: 'bools',
+                    string: 'strings',
+                    number: 'numbers'
+                };
+                return arrayFlagKeys[key];
+            }).filter(Boolean).pop();
+            // assign key to be coerced
+            if (assignment) {
+                flags[assignment][key] = true;
+            }
+            flags.arrays[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.boolean || []).filter(Boolean).forEach(function (key) {
+            flags.bools[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.string || []).filter(Boolean).forEach(function (key) {
+            flags.strings[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.number || []).filter(Boolean).forEach(function (key) {
+            flags.numbers[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.count || []).filter(Boolean).forEach(function (key) {
+            flags.counts[key] = true;
+            flags.keys.push(key);
+        });
+        [].concat(opts.normalize || []).filter(Boolean).forEach(function (key) {
+            flags.normalize[key] = true;
+            flags.keys.push(key);
+        });
+        if (typeof opts.narg === 'object') {
+            Object.entries(opts.narg).forEach(([key, value]) => {
+                if (typeof value === 'number') {
+                    flags.nargs[key] = value;
+                    flags.keys.push(key);
+                }
+            });
+        }
+        if (typeof opts.coerce === 'object') {
+            Object.entries(opts.coerce).forEach(([key, value]) => {
+                if (typeof value === 'function') {
+                    flags.coercions[key] = value;
+                    flags.keys.push(key);
+                }
+            });
+        }
+        if (typeof opts.config !== 'undefined') {
+            if (Array.isArray(opts.config) || typeof opts.config === 'string') {
+                ;
+                [].concat(opts.config).filter(Boolean).forEach(function (key) {
+                    flags.configs[key] = true;
+                });
+            }
+            else if (typeof opts.config === 'object') {
+                Object.entries(opts.config).forEach(([key, value]) => {
+                    if (typeof value === 'boolean' || typeof value === 'function') {
+                        flags.configs[key] = value;
+                    }
+                });
+            }
+        }
+        // create a lookup table that takes into account all
+        // combinations of aliases: {f: ['foo'], foo: ['f']}
+        extendAliases(opts.key, aliases, opts.default, flags.arrays);
+        // apply default values to all aliases.
+        Object.keys(defaults).forEach(function (key) {
+            (flags.aliases[key] || []).forEach(function (alias) {
+                defaults[alias] = defaults[key];
+            });
+        });
+        let error = null;
+        checkConfiguration();
+        let notFlags = [];
+        const argv = Object.assign(Object.create(null), { _: [] });
+        // TODO(bcoe): for the first pass at removing object prototype  we didn't
+        // remove all prototypes from objects returned by this API, we might want
+        // to gradually move towards doing so.
+        const argvReturn = {};
+        for (let i = 0; i < args.length; i++) {
+            const arg = args[i];
+            const truncatedArg = arg.replace(/^-{3,}/, '---');
+            let broken;
+            let key;
+            let letters;
+            let m;
+            let next;
+            let value;
+            // any unknown option (except for end-of-options, "--")
+            if (arg !== '--' && isUnknownOptionAsArg(arg)) {
+                pushPositional(arg);
+                // ---, ---=, ----, etc,
+            }
+            else if (truncatedArg.match(/---+(=|$)/)) {
+                // options without key name are invalid.
+                pushPositional(arg);
+                continue;
+                // -- separated by =
+            }
+            else if (arg.match(/^--.+=/) || (!configuration['short-option-groups'] && arg.match(/^-.+=/))) {
+                // Using [\s\S] instead of . because js doesn't support the
+                // 'dotall' regex modifier. See:
+                // http://stackoverflow.com/a/1068308/13216
+                m = arg.match(/^--?([^=]+)=([\s\S]*)$/);
+                // arrays format = '--f=a b c'
+                if (m !== null && Array.isArray(m) && m.length >= 3) {
+                    if (checkAllAliases(m[1], flags.arrays)) {
+                        i = eatArray(i, m[1], args, m[2]);
+                    }
+                    else if (checkAllAliases(m[1], flags.nargs) !== false) {
+                        // nargs format = '--f=monkey washing cat'
+                        i = eatNargs(i, m[1], args, m[2]);
+                    }
+                    else {
+                        setArg(m[1], m[2]);
+                    }
+                }
+            }
+            else if (arg.match(negatedBoolean) && configuration['boolean-negation']) {
+                m = arg.match(negatedBoolean);
+                if (m !== null && Array.isArray(m) && m.length >= 2) {
+                    key = m[1];
+                    setArg(key, checkAllAliases(key, flags.arrays) ? [false] : false);
+                }
+                // -- separated by space.
+            }
+            else if (arg.match(/^--.+/) || (!configuration['short-option-groups'] && arg.match(/^-[^-]+/))) {
+                m = arg.match(/^--?(.+)/);
+                if (m !== null && Array.isArray(m) && m.length >= 2) {
+                    key = m[1];
+                    if (checkAllAliases(key, flags.arrays)) {
+                        // array format = '--foo a b c'
+                        i = eatArray(i, key, args);
+                    }
+                    else if (checkAllAliases(key, flags.nargs) !== false) {
+                        // nargs format = '--foo a b c'
+                        // should be truthy even if: flags.nargs[key] === 0
+                        i = eatNargs(i, key, args);
+                    }
+                    else {
+                        next = args[i + 1];
+                        if (next !== undefined && (!next.match(/^-/) ||
+                            next.match(negative)) &&
+                            !checkAllAliases(key, flags.bools) &&
+                            !checkAllAliases(key, flags.counts)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else if (/^(true|false)$/.test(next)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else {
+                            setArg(key, defaultValue(key));
+                        }
+                    }
+                }
+                // dot-notation flag separated by '='.
+            }
+            else if (arg.match(/^-.\..+=/)) {
+                m = arg.match(/^-([^=]+)=([\s\S]*)$/);
+                if (m !== null && Array.isArray(m) && m.length >= 3) {
+                    setArg(m[1], m[2]);
+                }
+                // dot-notation flag separated by space.
+            }
+            else if (arg.match(/^-.\..+/) && !arg.match(negative)) {
+                next = args[i + 1];
+                m = arg.match(/^-(.\..+)/);
+                if (m !== null && Array.isArray(m) && m.length >= 2) {
+                    key = m[1];
+                    if (next !== undefined && !next.match(/^-/) &&
+                        !checkAllAliases(key, flags.bools) &&
+                        !checkAllAliases(key, flags.counts)) {
+                        setArg(key, next);
+                        i++;
+                    }
+                    else {
+                        setArg(key, defaultValue(key));
+                    }
+                }
+            }
+            else if (arg.match(/^-[^-]+/) && !arg.match(negative)) {
+                letters = arg.slice(1, -1).split('');
+                broken = false;
+                for (let j = 0; j < letters.length; j++) {
+                    next = arg.slice(j + 2);
+                    if (letters[j + 1] && letters[j + 1] === '=') {
+                        value = arg.slice(j + 3);
+                        key = letters[j];
+                        if (checkAllAliases(key, flags.arrays)) {
+                            // array format = '-f=a b c'
+                            i = eatArray(i, key, args, value);
+                        }
+                        else if (checkAllAliases(key, flags.nargs) !== false) {
+                            // nargs format = '-f=monkey washing cat'
+                            i = eatNargs(i, key, args, value);
+                        }
+                        else {
+                            setArg(key, value);
+                        }
+                        broken = true;
+                        break;
+                    }
+                    if (next === '-') {
+                        setArg(letters[j], next);
+                        continue;
+                    }
+                    // current letter is an alphabetic character and next value is a number
+                    if (/[A-Za-z]/.test(letters[j]) &&
+                        /^-?\d+(\.\d*)?(e-?\d+)?$/.test(next) &&
+                        checkAllAliases(next, flags.bools) === false) {
+                        setArg(letters[j], next);
+                        broken = true;
+                        break;
+                    }
+                    if (letters[j + 1] && letters[j + 1].match(/\W/)) {
+                        setArg(letters[j], next);
+                        broken = true;
+                        break;
+                    }
+                    else {
+                        setArg(letters[j], defaultValue(letters[j]));
+                    }
+                }
+                key = arg.slice(-1)[0];
+                if (!broken && key !== '-') {
+                    if (checkAllAliases(key, flags.arrays)) {
+                        // array format = '-f a b c'
+                        i = eatArray(i, key, args);
+                    }
+                    else if (checkAllAliases(key, flags.nargs) !== false) {
+                        // nargs format = '-f a b c'
+                        // should be truthy even if: flags.nargs[key] === 0
+                        i = eatNargs(i, key, args);
+                    }
+                    else {
+                        next = args[i + 1];
+                        if (next !== undefined && (!/^(-|--)[^-]/.test(next) ||
+                            next.match(negative)) &&
+                            !checkAllAliases(key, flags.bools) &&
+                            !checkAllAliases(key, flags.counts)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else if (/^(true|false)$/.test(next)) {
+                            setArg(key, next);
+                            i++;
+                        }
+                        else {
+                            setArg(key, defaultValue(key));
+                        }
+                    }
+                }
+            }
+            else if (arg.match(/^-[0-9]$/) &&
+                arg.match(negative) &&
+                checkAllAliases(arg.slice(1), flags.bools)) {
+                // single-digit boolean alias, e.g: xargs -0
+                key = arg.slice(1);
+                setArg(key, defaultValue(key));
+            }
+            else if (arg === '--') {
+                notFlags = args.slice(i + 1);
+                break;
+            }
+            else if (configuration['halt-at-non-option']) {
+                notFlags = args.slice(i);
+                break;
+            }
+            else {
+                pushPositional(arg);
+            }
+        }
+        // order of precedence:
+        // 1. command line arg
+        // 2. value from env var
+        // 3. value from config file
+        // 4. value from config objects
+        // 5. configured default value
+        applyEnvVars(argv, true); // special case: check env vars that point to config file
+        applyEnvVars(argv, false);
+        setConfig(argv);
+        setConfigObjects();
+        applyDefaultsAndAliases(argv, flags.aliases, defaults, true);
+        applyCoercions(argv);
+        if (configuration['set-placeholder-key'])
+            setPlaceholderKeys(argv);
+        // for any counts either not in args or without an explicit default, set to 0
+        Object.keys(flags.counts).forEach(function (key) {
+            if (!hasKey(argv, key.split('.')))
+                setArg(key, 0);
+        });
+        // '--' defaults to undefined.
+        if (notFlagsOption && notFlags.length)
+            argv[notFlagsArgv] = [];
+        notFlags.forEach(function (key) {
+            argv[notFlagsArgv].push(key);
+        });
+        if (configuration['camel-case-expansion'] && configuration['strip-dashed']) {
+            Object.keys(argv).filter(key => key !== '--' && key.includes('-')).forEach(key => {
+                delete argv[key];
+            });
+        }
+        if (configuration['strip-aliased']) {
+            ;
+            [].concat(...Object.keys(aliases).map(k => aliases[k])).forEach(alias => {
+                if (configuration['camel-case-expansion'] && alias.includes('-')) {
+                    delete argv[alias.split('.').map(prop => camelCase(prop)).join('.')];
+                }
+                delete argv[alias];
+            });
+        }
+        // Push argument into positional array, applying numeric coercion:
+        function pushPositional(arg) {
+            const maybeCoercedNumber = maybeCoerceNumber('_', arg);
+            if (typeof maybeCoercedNumber === 'string' || typeof maybeCoercedNumber === 'number') {
+                argv._.push(maybeCoercedNumber);
+            }
+        }
+        // how many arguments should we consume, based
+        // on the nargs option?
+        function eatNargs(i, key, args, argAfterEqualSign) {
+            let ii;
+            let toEat = checkAllAliases(key, flags.nargs);
+            // NaN has a special meaning for the array type, indicating that one or
+            // more values are expected.
+            toEat = typeof toEat !== 'number' || isNaN(toEat) ? 1 : toEat;
+            if (toEat === 0) {
+                if (!isUndefined(argAfterEqualSign)) {
+                    error = Error(__('Argument unexpected for: %s', key));
+                }
+                setArg(key, defaultValue(key));
+                return i;
+            }
+            let available = isUndefined(argAfterEqualSign) ? 0 : 1;
+            if (configuration['nargs-eats-options']) {
+                // classic behavior, yargs eats positional and dash arguments.
+                if (args.length - (i + 1) + available < toEat) {
+                    error = Error(__('Not enough arguments following: %s', key));
+                }
+                available = toEat;
+            }
+            else {
+                // nargs will not consume flag arguments, e.g., -abc, --foo,
+                // and terminates when one is observed.
+                for (ii = i + 1; ii < args.length; ii++) {
+                    if (!args[ii].match(/^-[^0-9]/) || args[ii].match(negative) || isUnknownOptionAsArg(args[ii]))
+                        available++;
+                    else
+                        break;
+                }
+                if (available < toEat)
+                    error = Error(__('Not enough arguments following: %s', key));
+            }
+            let consumed = Math.min(available, toEat);
+            if (!isUndefined(argAfterEqualSign) && consumed > 0) {
+                setArg(key, argAfterEqualSign);
+                consumed--;
+            }
+            for (ii = i + 1; ii < (consumed + i + 1); ii++) {
+                setArg(key, args[ii]);
+            }
+            return (i + consumed);
+        }
+        // if an option is an array, eat all non-hyphenated arguments
+        // following it... YUM!
+        // e.g., --foo apple banana cat becomes ["apple", "banana", "cat"]
+        function eatArray(i, key, args, argAfterEqualSign) {
+            let argsToSet = [];
+            let next = argAfterEqualSign || args[i + 1];
+            // If both array and nargs are configured, enforce the nargs count:
+            const nargsCount = checkAllAliases(key, flags.nargs);
+            if (checkAllAliases(key, flags.bools) && !(/^(true|false)$/.test(next))) {
+                argsToSet.push(true);
+            }
+            else if (isUndefined(next) ||
+                (isUndefined(argAfterEqualSign) && /^-/.test(next) && !negative.test(next) && !isUnknownOptionAsArg(next))) {
+                // for keys without value ==> argsToSet remains an empty []
+                // set user default value, if available
+                if (defaults[key] !== undefined) {
+                    const defVal = defaults[key];
+                    argsToSet = Array.isArray(defVal) ? defVal : [defVal];
+                }
+            }
+            else {
+                // value in --option=value is eaten as is
+                if (!isUndefined(argAfterEqualSign)) {
+                    argsToSet.push(processValue(key, argAfterEqualSign));
+                }
+                for (let ii = i + 1; ii < args.length; ii++) {
+                    if ((!configuration['greedy-arrays'] && argsToSet.length > 0) ||
+                        (nargsCount && typeof nargsCount === 'number' && argsToSet.length >= nargsCount))
+                        break;
+                    next = args[ii];
+                    if (/^-/.test(next) && !negative.test(next) && !isUnknownOptionAsArg(next))
+                        break;
+                    i = ii;
+                    argsToSet.push(processValue(key, next));
+                }
+            }
+            // If both array and nargs are configured, create an error if less than
+            // nargs positionals were found. NaN has special meaning, indicating
+            // that at least one value is required (more are okay).
+            if (typeof nargsCount === 'number' && ((nargsCount && argsToSet.length < nargsCount) ||
+                (isNaN(nargsCount) && argsToSet.length === 0))) {
+                error = Error(__('Not enough arguments following: %s', key));
+            }
+            setArg(key, argsToSet);
+            return i;
+        }
+        function setArg(key, val) {
+            if (/-/.test(key) && configuration['camel-case-expansion']) {
+                const alias = key.split('.').map(function (prop) {
+                    return camelCase(prop);
+                }).join('.');
+                addNewAlias(key, alias);
+            }
+            const value = processValue(key, val);
+            const splitKey = key.split('.');
+            setKey(argv, splitKey, value);
+            // handle populating aliases of the full key
+            if (flags.aliases[key]) {
+                flags.aliases[key].forEach(function (x) {
+                    const keyProperties = x.split('.');
+                    setKey(argv, keyProperties, value);
+                });
+            }
+            // handle populating aliases of the first element of the dot-notation key
+            if (splitKey.length > 1 && configuration['dot-notation']) {
+                ;
+                (flags.aliases[splitKey[0]] || []).forEach(function (x) {
+                    let keyProperties = x.split('.');
+                    // expand alias with nested objects in key
+                    const a = [].concat(splitKey);
+                    a.shift(); // nuke the old key.
+                    keyProperties = keyProperties.concat(a);
+                    // populate alias only if is not already an alias of the full key
+                    // (already populated above)
+                    if (!(flags.aliases[key] || []).includes(keyProperties.join('.'))) {
+                        setKey(argv, keyProperties, value);
+                    }
+                });
+            }
+            // Set normalize getter and setter when key is in 'normalize' but isn't an array
+            if (checkAllAliases(key, flags.normalize) && !checkAllAliases(key, flags.arrays)) {
+                const keys = [key].concat(flags.aliases[key] || []);
+                keys.forEach(function (key) {
+                    Object.defineProperty(argvReturn, key, {
+                        enumerable: true,
+                        get() {
+                            return val;
+                        },
+                        set(value) {
+                            val = typeof value === 'string' ? mixin.normalize(value) : value;
+                        }
+                    });
+                });
+            }
+        }
+        function addNewAlias(key, alias) {
+            if (!(flags.aliases[key] && flags.aliases[key].length)) {
+                flags.aliases[key] = [alias];
+                newAliases[alias] = true;
+            }
+            if (!(flags.aliases[alias] && flags.aliases[alias].length)) {
+                addNewAlias(alias, key);
+            }
+        }
+        function processValue(key, val) {
+            // strings may be quoted, clean this up as we assign values.
+            if (typeof val === 'string' &&
+                (val[0] === "'" || val[0] === '"') &&
+                val[val.length - 1] === val[0]) {
+                val = val.substring(1, val.length - 1);
+            }
+            // handle parsing boolean arguments --foo=true --bar false.
+            if (checkAllAliases(key, flags.bools) || checkAllAliases(key, flags.counts)) {
+                if (typeof val === 'string')
+                    val = val === 'true';
+            }
+            let value = Array.isArray(val)
+                ? val.map(function (v) { return maybeCoerceNumber(key, v); })
+                : maybeCoerceNumber(key, val);
+            // increment a count given as arg (either no value or value parsed as boolean)
+            if (checkAllAliases(key, flags.counts) && (isUndefined(value) || typeof value === 'boolean')) {
+                value = increment();
+            }
+            // Set normalized value when key is in 'normalize' and in 'arrays'
+            if (checkAllAliases(key, flags.normalize) && checkAllAliases(key, flags.arrays)) {
+                if (Array.isArray(val))
+                    value = val.map((val) => { return mixin.normalize(val); });
+                else
+                    value = mixin.normalize(val);
+            }
+            return value;
+        }
+        function maybeCoerceNumber(key, value) {
+            if (!configuration['parse-positional-numbers'] && key === '_')
+                return value;
+            if (!checkAllAliases(key, flags.strings) && !checkAllAliases(key, flags.bools) && !Array.isArray(value)) {
+                const shouldCoerceNumber = looksLikeNumber(value) && configuration['parse-numbers'] && (Number.isSafeInteger(Math.floor(parseFloat(`${value}`))));
+                if (shouldCoerceNumber || (!isUndefined(value) && checkAllAliases(key, flags.numbers))) {
+                    value = Number(value);
+                }
+            }
+            return value;
+        }
+        // set args from config.json file, this should be
+        // applied last so that defaults can be applied.
+        function setConfig(argv) {
+            const configLookup = Object.create(null);
+            // expand defaults/aliases, in-case any happen to reference
+            // the config.json file.
+            applyDefaultsAndAliases(configLookup, flags.aliases, defaults);
+            Object.keys(flags.configs).forEach(function (configKey) {
+                const configPath = argv[configKey] || configLookup[configKey];
+                if (configPath) {
+                    try {
+                        let config = null;
+                        const resolvedConfigPath = mixin.resolve(mixin.cwd(), configPath);
+                        const resolveConfig = flags.configs[configKey];
+                        if (typeof resolveConfig === 'function') {
+                            try {
+                                config = resolveConfig(resolvedConfigPath);
+                            }
+                            catch (e) {
+                                config = e;
+                            }
+                            if (config instanceof Error) {
+                                error = config;
+                                return;
+                            }
+                        }
+                        else {
+                            config = mixin.require(resolvedConfigPath);
+                        }
+                        setConfigObject(config);
+                    }
+                    catch (ex) {
+                        // Deno will receive a PermissionDenied error if an attempt is
+                        // made to load config without the --allow-read flag:
+                        if (ex.name === 'PermissionDenied')
+                            error = ex;
+                        else if (argv[configKey])
+                            error = Error(__('Invalid JSON config file: %s', configPath));
+                    }
+                }
+            });
+        }
+        // set args from config object.
+        // it recursively checks nested objects.
+        function setConfigObject(config, prev) {
+            Object.keys(config).forEach(function (key) {
+                const value = config[key];
+                const fullKey = prev ? prev + '.' + key : key;
+                // if the value is an inner object and we have dot-notation
+                // enabled, treat inner objects in config the same as
+                // heavily nested dot notations (foo.bar.apple).
+                if (typeof value === 'object' && value !== null && !Array.isArray(value) && configuration['dot-notation']) {
+                    // if the value is an object but not an array, check nested object
+                    setConfigObject(value, fullKey);
+                }
+                else {
+                    // setting arguments via CLI takes precedence over
+                    // values within the config file.
+                    if (!hasKey(argv, fullKey.split('.')) || (checkAllAliases(fullKey, flags.arrays) && configuration['combine-arrays'])) {
+                        setArg(fullKey, value);
+                    }
+                }
+            });
+        }
+        // set all config objects passed in opts
+        function setConfigObjects() {
+            if (typeof configObjects !== 'undefined') {
+                configObjects.forEach(function (configObject) {
+                    setConfigObject(configObject);
+                });
+            }
+        }
+        function applyEnvVars(argv, configOnly) {
+            if (typeof envPrefix === 'undefined')
+                return;
+            const prefix = typeof envPrefix === 'string' ? envPrefix : '';
+            const env = mixin.env();
+            Object.keys(env).forEach(function (envVar) {
+                if (prefix === '' || envVar.lastIndexOf(prefix, 0) === 0) {
+                    // get array of nested keys and convert them to camel case
+                    const keys = envVar.split('__').map(function (key, i) {
+                        if (i === 0) {
+                            key = key.substring(prefix.length);
+                        }
+                        return camelCase(key);
+                    });
+                    if (((configOnly && flags.configs[keys.join('.')]) || !configOnly) && !hasKey(argv, keys)) {
+                        setArg(keys.join('.'), env[envVar]);
+                    }
+                }
+            });
+        }
+        function applyCoercions(argv) {
+            let coerce;
+            const applied = new Set();
+            Object.keys(argv).forEach(function (key) {
+                if (!applied.has(key)) { // If we haven't already coerced this option via one of its aliases
+                    coerce = checkAllAliases(key, flags.coercions);
+                    if (typeof coerce === 'function') {
+                        try {
+                            const value = maybeCoerceNumber(key, coerce(argv[key]));
+                            ([].concat(flags.aliases[key] || [], key)).forEach(ali => {
+                                applied.add(ali);
+                                argv[ali] = value;
+                            });
+                        }
+                        catch (err) {
+                            error = err;
+                        }
+                    }
+                }
+            });
+        }
+        function setPlaceholderKeys(argv) {
+            flags.keys.forEach((key) => {
+                // don't set placeholder keys for dot notation options 'foo.bar'.
+                if (~key.indexOf('.'))
+                    return;
+                if (typeof argv[key] === 'undefined')
+                    argv[key] = undefined;
+            });
+            return argv;
+        }
+        function applyDefaultsAndAliases(obj, aliases, defaults, canLog = false) {
+            Object.keys(defaults).forEach(function (key) {
+                if (!hasKey(obj, key.split('.'))) {
+                    setKey(obj, key.split('.'), defaults[key]);
+                    if (canLog)
+                        defaulted[key] = true;
+                    (aliases[key] || []).forEach(function (x) {
+                        if (hasKey(obj, x.split('.')))
+                            return;
+                        setKey(obj, x.split('.'), defaults[key]);
+                    });
+                }
+            });
+        }
+        function hasKey(obj, keys) {
+            let o = obj;
+            if (!configuration['dot-notation'])
+                keys = [keys.join('.')];
+            keys.slice(0, -1).forEach(function (key) {
+                o = (o[key] || {});
+            });
+            const key = keys[keys.length - 1];
+            if (typeof o !== 'object')
+                return false;
+            else
+                return key in o;
+        }
+        function setKey(obj, keys, value) {
+            let o = obj;
+            if (!configuration['dot-notation'])
+                keys = [keys.join('.')];
+            keys.slice(0, -1).forEach(function (key) {
+                // TODO(bcoe): in the next major version of yargs, switch to
+                // Object.create(null) for dot notation:
+                key = sanitizeKey(key);
+                if (typeof o === 'object' && o[key] === undefined) {
+                    o[key] = {};
+                }
+                if (typeof o[key] !== 'object' || Array.isArray(o[key])) {
+                    // ensure that o[key] is an array, and that the last item is an empty object.
+                    if (Array.isArray(o[key])) {
+                        o[key].push({});
+                    }
+                    else {
+                        o[key] = [o[key], {}];
+                    }
+                    // we want to update the empty object at the end of the o[key] array, so set o to that object
+                    o = o[key][o[key].length - 1];
+                }
+                else {
+                    o = o[key];
+                }
+            });
+            // TODO(bcoe): in the next major version of yargs, switch to
+            // Object.create(null) for dot notation:
+            const key = sanitizeKey(keys[keys.length - 1]);
+            const isTypeArray = checkAllAliases(keys.join('.'), flags.arrays);
+            const isValueArray = Array.isArray(value);
+            let duplicate = configuration['duplicate-arguments-array'];
+            // nargs has higher priority than duplicate
+            if (!duplicate && checkAllAliases(key, flags.nargs)) {
+                duplicate = true;
+                if ((!isUndefined(o[key]) && flags.nargs[key] === 1) || (Array.isArray(o[key]) && o[key].length === flags.nargs[key])) {
+                    o[key] = undefined;
+                }
+            }
+            if (value === increment()) {
+                o[key] = increment(o[key]);
+            }
+            else if (Array.isArray(o[key])) {
+                if (duplicate && isTypeArray && isValueArray) {
+                    o[key] = configuration['flatten-duplicate-arrays'] ? o[key].concat(value) : (Array.isArray(o[key][0]) ? o[key] : [o[key]]).concat([value]);
+                }
+                else if (!duplicate && Boolean(isTypeArray) === Boolean(isValueArray)) {
+                    o[key] = value;
+                }
+                else {
+                    o[key] = o[key].concat([value]);
+                }
+            }
+            else if (o[key] === undefined && isTypeArray) {
+                o[key] = isValueArray ? value : [value];
+            }
+            else if (duplicate && !(o[key] === undefined ||
+                checkAllAliases(key, flags.counts) ||
+                checkAllAliases(key, flags.bools))) {
+                o[key] = [o[key], value];
+            }
+            else {
+                o[key] = value;
+            }
+        }
+        // extend the aliases list with inferred aliases.
+        function extendAliases(...args) {
+            args.forEach(function (obj) {
+                Object.keys(obj || {}).forEach(function (key) {
+                    // short-circuit if we've already added a key
+                    // to the aliases array, for example it might
+                    // exist in both 'opts.default' and 'opts.key'.
+                    if (flags.aliases[key])
+                        return;
+                    flags.aliases[key] = [].concat(aliases[key] || []);
+                    // For "--option-name", also set argv.optionName
+                    flags.aliases[key].concat(key).forEach(function (x) {
+                        if (/-/.test(x) && configuration['camel-case-expansion']) {
+                            const c = camelCase(x);
+                            if (c !== key && flags.aliases[key].indexOf(c) === -1) {
+                                flags.aliases[key].push(c);
+                                newAliases[c] = true;
+                            }
+                        }
+                    });
+                    // For "--optionName", also set argv['option-name']
+                    flags.aliases[key].concat(key).forEach(function (x) {
+                        if (x.length > 1 && /[A-Z]/.test(x) && configuration['camel-case-expansion']) {
+                            const c = decamelize(x, '-');
+                            if (c !== key && flags.aliases[key].indexOf(c) === -1) {
+                                flags.aliases[key].push(c);
+                                newAliases[c] = true;
+                            }
+                        }
+                    });
+                    flags.aliases[key].forEach(function (x) {
+                        flags.aliases[x] = [key].concat(flags.aliases[key].filter(function (y) {
+                            return x !== y;
+                        }));
+                    });
+                });
+            });
+        }
+        function checkAllAliases(key, flag) {
+            const toCheck = [].concat(flags.aliases[key] || [], key);
+            const keys = Object.keys(flag);
+            const setAlias = toCheck.find(key => keys.includes(key));
+            return setAlias ? flag[setAlias] : false;
+        }
+        function hasAnyFlag(key) {
+            const flagsKeys = Object.keys(flags);
+            const toCheck = [].concat(flagsKeys.map(k => flags[k]));
+            return toCheck.some(function (flag) {
+                return Array.isArray(flag) ? flag.includes(key) : flag[key];
+            });
+        }
+        function hasFlagsMatching(arg, ...patterns) {
+            const toCheck = [].concat(...patterns);
+            return toCheck.some(function (pattern) {
+                const match = arg.match(pattern);
+                return match && hasAnyFlag(match[1]);
+            });
+        }
+        // based on a simplified version of the short flag group parsing logic
+        function hasAllShortFlags(arg) {
+            // if this is a negative number, or doesn't start with a single hyphen, it's not a short flag group
+            if (arg.match(negative) || !arg.match(/^-[^-]+/)) {
+                return false;
+            }
+            let hasAllFlags = true;
+            let next;
+            const letters = arg.slice(1).split('');
+            for (let j = 0; j < letters.length; j++) {
+                next = arg.slice(j + 2);
+                if (!hasAnyFlag(letters[j])) {
+                    hasAllFlags = false;
+                    break;
+                }
+                if ((letters[j + 1] && letters[j + 1] === '=') ||
+                    next === '-' ||
+                    (/[A-Za-z]/.test(letters[j]) && /^-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) ||
+                    (letters[j + 1] && letters[j + 1].match(/\W/))) {
+                    break;
+                }
+            }
+            return hasAllFlags;
+        }
+        function isUnknownOptionAsArg(arg) {
+            return configuration['unknown-options-as-args'] && isUnknownOption(arg);
+        }
+        function isUnknownOption(arg) {
+            arg = arg.replace(/^-{3,}/, '--');
+            // ignore negative numbers
+            if (arg.match(negative)) {
+                return false;
+            }
+            // if this is a short option group and all of them are configured, it isn't unknown
+            if (hasAllShortFlags(arg)) {
+                return false;
+            }
+            // e.g. '--count=2'
+            const flagWithEquals = /^-+([^=]+?)=[\s\S]*$/;
+            // e.g. '-a' or '--arg'
+            const normalFlag = /^-+([^=]+?)$/;
+            // e.g. '-a-'
+            const flagEndingInHyphen = /^-+([^=]+?)-$/;
+            // e.g. '-abc123'
+            const flagEndingInDigits = /^-+([^=]+?\d+)$/;
+            // e.g. '-a/usr/local'
+            const flagEndingInNonWordCharacters = /^-+([^=]+?)\W+.*$/;
+            // check the different types of flag styles, including negatedBoolean, a pattern defined near the start of the parse method
+            return !hasFlagsMatching(arg, flagWithEquals, negatedBoolean, normalFlag, flagEndingInHyphen, flagEndingInDigits, flagEndingInNonWordCharacters);
+        }
+        // make a best effort to pick a default value
+        // for an option based on name and type.
+        function defaultValue(key) {
+            if (!checkAllAliases(key, flags.bools) &&
+                !checkAllAliases(key, flags.counts) &&
+                `${key}` in defaults) {
+                return defaults[key];
+            }
+            else {
+                return defaultForType(guessType(key));
+            }
+        }
+        // return a default value, given the type of a flag.,
+        function defaultForType(type) {
+            const def = {
+                [DefaultValuesForTypeKey.BOOLEAN]: true,
+                [DefaultValuesForTypeKey.STRING]: '',
+                [DefaultValuesForTypeKey.NUMBER]: undefined,
+                [DefaultValuesForTypeKey.ARRAY]: []
+            };
+            return def[type];
+        }
+        // given a flag, enforce a default type.
+        function guessType(key) {
+            let type = DefaultValuesForTypeKey.BOOLEAN;
+            if (checkAllAliases(key, flags.strings))
+                type = DefaultValuesForTypeKey.STRING;
+            else if (checkAllAliases(key, flags.numbers))
+                type = DefaultValuesForTypeKey.NUMBER;
+            else if (checkAllAliases(key, flags.bools))
+                type = DefaultValuesForTypeKey.BOOLEAN;
+            else if (checkAllAliases(key, flags.arrays))
+                type = DefaultValuesForTypeKey.ARRAY;
+            return type;
+        }
+        function isUndefined(num) {
+            return num === undefined;
+        }
+        // check user configuration settings for inconsistencies
+        function checkConfiguration() {
+            // count keys should not be set as array/narg
+            Object.keys(flags.counts).find(key => {
+                if (checkAllAliases(key, flags.arrays)) {
+                    error = Error(__('Invalid configuration: %s, opts.count excludes opts.array.', key));
+                    return true;
+                }
+                else if (checkAllAliases(key, flags.nargs)) {
+                    error = Error(__('Invalid configuration: %s, opts.count excludes opts.narg.', key));
+                    return true;
+                }
+                return false;
+            });
+        }
+        return {
+            aliases: Object.assign({}, flags.aliases),
+            argv: Object.assign(argvReturn, argv),
+            configuration: configuration,
+            defaulted: Object.assign({}, defaulted),
+            error: error,
+            newAliases: Object.assign({}, newAliases)
+        };
+    }
+}
+// if any aliases reference each other, we should
+// merge them together.
+function combineAliases(aliases) {
+    const aliasArrays = [];
+    const combined = Object.create(null);
+    let change = true;
+    // turn alias lookup hash {key: ['alias1', 'alias2']} into
+    // a simple array ['key', 'alias1', 'alias2']
+    Object.keys(aliases).forEach(function (key) {
+        aliasArrays.push([].concat(aliases[key], key));
+    });
+    // combine arrays until zero changes are
+    // made in an iteration.
+    while (change) {
+        change = false;
+        for (let i = 0; i < aliasArrays.length; i++) {
+            for (let ii = i + 1; ii < aliasArrays.length; ii++) {
+                const intersect = aliasArrays[i].filter(function (v) {
+                    return aliasArrays[ii].indexOf(v) !== -1;
+                });
+                if (intersect.length) {
+                    aliasArrays[i] = aliasArrays[i].concat(aliasArrays[ii]);
+                    aliasArrays.splice(ii, 1);
+                    change = true;
+                    break;
+                }
+            }
+        }
+    }
+    // map arrays back to the hash-lookup (de-dupe while
+    // we're at it).
+    aliasArrays.forEach(function (aliasArray) {
+        aliasArray = aliasArray.filter(function (v, i, self) {
+            return self.indexOf(v) === i;
+        });
+        const lastAlias = aliasArray.pop();
+        if (lastAlias !== undefined && typeof lastAlias === 'string') {
+            combined[lastAlias] = aliasArray;
+        }
+    });
+    return combined;
+}
+// this function should only be called when a count is given as an arg
+// it is NOT called to set a default value
+// thus we can start the count at 1 instead of 0
+function increment(orig) {
+    return orig !== undefined ? orig + 1 : 1;
+}
+// TODO(bcoe): in the next major version of yargs, switch to
+// Object.create(null) for dot notation:
+function sanitizeKey(key) {
+    if (key === '__proto__')
+        return '___proto___';
+    return key;
+}
