Index: imaps-frontend/node_modules/webpack/lib/ModuleGraph.js
===================================================================
--- imaps-frontend/node_modules/webpack/lib/ModuleGraph.js	(revision 79a03170cdde4e801d12257ee86723774970427b)
+++ imaps-frontend/node_modules/webpack/lib/ModuleGraph.js	(revision 79a03170cdde4e801d12257ee86723774970427b)
@@ -0,0 +1,896 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+const util = require("util");
+const ExportsInfo = require("./ExportsInfo");
+const ModuleGraphConnection = require("./ModuleGraphConnection");
+const SortableSet = require("./util/SortableSet");
+const WeakTupleMap = require("./util/WeakTupleMap");
+
+/** @typedef {import("./DependenciesBlock")} DependenciesBlock */
+/** @typedef {import("./Dependency")} Dependency */
+/** @typedef {import("./ExportsInfo").ExportInfo} ExportInfo */
+/** @typedef {import("./Module")} Module */
+/** @typedef {import("./ModuleProfile")} ModuleProfile */
+/** @typedef {import("./RequestShortener")} RequestShortener */
+/** @typedef {import("./util/runtime").RuntimeSpec} RuntimeSpec */
+
+/**
+ * @callback OptimizationBailoutFunction
+ * @param {RequestShortener} requestShortener
+ * @returns {string}
+ */
+
+const EMPTY_SET = new Set();
+
+/**
+ * @param {SortableSet<ModuleGraphConnection>} set input
+ * @returns {readonly Map<Module | undefined, readonly ModuleGraphConnection[]>} mapped by origin module
+ */
+const getConnectionsByOriginModule = set => {
+	const map = new Map();
+	/** @type {Module | 0} */
+	let lastModule = 0;
+	/** @type {ModuleGraphConnection[] | undefined} */
+	let lastList;
+	for (const connection of set) {
+		const { originModule } = connection;
+		if (lastModule === originModule) {
+			/** @type {ModuleGraphConnection[]} */
+			(lastList).push(connection);
+		} else {
+			lastModule = /** @type {Module} */ (originModule);
+			const list = map.get(originModule);
+			if (list !== undefined) {
+				lastList = list;
+				list.push(connection);
+			} else {
+				const list = [connection];
+				lastList = list;
+				map.set(originModule, list);
+			}
+		}
+	}
+	return map;
+};
+
+/**
+ * @param {SortableSet<ModuleGraphConnection>} set input
+ * @returns {readonly Map<Module | undefined, readonly ModuleGraphConnection[]>} mapped by module
+ */
+const getConnectionsByModule = set => {
+	const map = new Map();
+	/** @type {Module | 0} */
+	let lastModule = 0;
+	/** @type {ModuleGraphConnection[] | undefined} */
+	let lastList;
+	for (const connection of set) {
+		const { module } = connection;
+		if (lastModule === module) {
+			/** @type {ModuleGraphConnection[]} */
+			(lastList).push(connection);
+		} else {
+			lastModule = module;
+			const list = map.get(module);
+			if (list !== undefined) {
+				lastList = list;
+				list.push(connection);
+			} else {
+				const list = [connection];
+				lastList = list;
+				map.set(module, list);
+			}
+		}
+	}
+	return map;
+};
+
+/** @typedef {SortableSet<ModuleGraphConnection>} IncomingConnections */
+/** @typedef {SortableSet<ModuleGraphConnection>} OutgoingConnections */
+
+class ModuleGraphModule {
+	constructor() {
+		/** @type {IncomingConnections} */
+		this.incomingConnections = new SortableSet();
+		/** @type {OutgoingConnections | undefined} */
+		this.outgoingConnections = undefined;
+		/** @type {Module | null | undefined} */
+		this.issuer = undefined;
+		/** @type {(string | OptimizationBailoutFunction)[]} */
+		this.optimizationBailout = [];
+		/** @type {ExportsInfo} */
+		this.exports = new ExportsInfo();
+		/** @type {number | null} */
+		this.preOrderIndex = null;
+		/** @type {number | null} */
+		this.postOrderIndex = null;
+		/** @type {number | null} */
+		this.depth = null;
+		/** @type {ModuleProfile | undefined} */
+		this.profile = undefined;
+		/** @type {boolean} */
+		this.async = false;
+		/** @type {ModuleGraphConnection[] | undefined} */
+		this._unassignedConnections = undefined;
+	}
+}
+
+class ModuleGraph {
+	constructor() {
+		/**
+		 * @type {WeakMap<Dependency, ModuleGraphConnection | null>}
+		 * @private
+		 */
+		this._dependencyMap = new WeakMap();
+		/**
+		 * @type {Map<Module, ModuleGraphModule>}
+		 * @private
+		 */
+		this._moduleMap = new Map();
+		/**
+		 * @type {WeakMap<any, object>}
+		 * @private
+		 */
+		this._metaMap = new WeakMap();
+		/**
+		 * @type {WeakTupleMap<any[], any> | undefined}
+		 * @private
+		 */
+		this._cache = undefined;
+		/**
+		 * @type {Map<Module, WeakTupleMap<any, any>> | undefined}
+		 * @private
+		 */
+		this._moduleMemCaches = undefined;
+
+		/**
+		 * @type {string | undefined}
+		 * @private
+		 */
+		this._cacheStage = undefined;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {ModuleGraphModule} the internal module
+	 */
+	_getModuleGraphModule(module) {
+		let mgm = this._moduleMap.get(module);
+		if (mgm === undefined) {
+			mgm = new ModuleGraphModule();
+			this._moduleMap.set(module, mgm);
+		}
+		return mgm;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency
+	 * @param {DependenciesBlock} block parent block
+	 * @param {Module} module parent module
+	 * @param {number=} indexInBlock position in block
+	 * @returns {void}
+	 */
+	setParents(dependency, block, module, indexInBlock = -1) {
+		dependency._parentDependenciesBlockIndex = indexInBlock;
+		dependency._parentDependenciesBlock = block;
+		dependency._parentModule = module;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency
+	 * @returns {Module | undefined} parent module
+	 */
+	getParentModule(dependency) {
+		return dependency._parentModule;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency
+	 * @returns {DependenciesBlock | undefined} parent block
+	 */
+	getParentBlock(dependency) {
+		return dependency._parentDependenciesBlock;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency
+	 * @returns {number} index
+	 */
+	getParentBlockIndex(dependency) {
+		return dependency._parentDependenciesBlockIndex;
+	}
+
+	/**
+	 * @param {Module | null} originModule the referencing module
+	 * @param {Dependency} dependency the referencing dependency
+	 * @param {Module} module the referenced module
+	 * @returns {void}
+	 */
+	setResolvedModule(originModule, dependency, module) {
+		const connection = new ModuleGraphConnection(
+			originModule,
+			dependency,
+			module,
+			undefined,
+			dependency.weak,
+			dependency.getCondition(this)
+		);
+		const connections = this._getModuleGraphModule(module).incomingConnections;
+		connections.add(connection);
+		if (originModule) {
+			const mgm = this._getModuleGraphModule(originModule);
+			if (mgm._unassignedConnections === undefined) {
+				mgm._unassignedConnections = [];
+			}
+			mgm._unassignedConnections.push(connection);
+			if (mgm.outgoingConnections === undefined) {
+				mgm.outgoingConnections = new SortableSet();
+			}
+			mgm.outgoingConnections.add(connection);
+		} else {
+			this._dependencyMap.set(dependency, connection);
+		}
+	}
+
+	/**
+	 * @param {Dependency} dependency the referencing dependency
+	 * @param {Module} module the referenced module
+	 * @returns {void}
+	 */
+	updateModule(dependency, module) {
+		const connection =
+			/** @type {ModuleGraphConnection} */
+			(this.getConnection(dependency));
+		if (connection.module === module) return;
+		const newConnection = connection.clone();
+		newConnection.module = module;
+		this._dependencyMap.set(dependency, newConnection);
+		connection.setActive(false);
+		const originMgm = this._getModuleGraphModule(
+			/** @type {Module} */ (connection.originModule)
+		);
+		/** @type {OutgoingConnections} */
+		(originMgm.outgoingConnections).add(newConnection);
+		const targetMgm = this._getModuleGraphModule(module);
+		targetMgm.incomingConnections.add(newConnection);
+	}
+
+	/**
+	 * @param {Dependency} dependency the referencing dependency
+	 * @returns {void}
+	 */
+	removeConnection(dependency) {
+		const connection =
+			/** @type {ModuleGraphConnection} */
+			(this.getConnection(dependency));
+		const targetMgm = this._getModuleGraphModule(connection.module);
+		targetMgm.incomingConnections.delete(connection);
+		const originMgm = this._getModuleGraphModule(
+			/** @type {Module} */ (connection.originModule)
+		);
+		/** @type {OutgoingConnections} */
+		(originMgm.outgoingConnections).delete(connection);
+		this._dependencyMap.set(dependency, null);
+	}
+
+	/**
+	 * @param {Dependency} dependency the referencing dependency
+	 * @param {string} explanation an explanation
+	 * @returns {void}
+	 */
+	addExplanation(dependency, explanation) {
+		const connection =
+			/** @type {ModuleGraphConnection} */
+			(this.getConnection(dependency));
+		connection.addExplanation(explanation);
+	}
+
+	/**
+	 * @param {Module} sourceModule the source module
+	 * @param {Module} targetModule the target module
+	 * @returns {void}
+	 */
+	cloneModuleAttributes(sourceModule, targetModule) {
+		const oldMgm = this._getModuleGraphModule(sourceModule);
+		const newMgm = this._getModuleGraphModule(targetModule);
+		newMgm.postOrderIndex = oldMgm.postOrderIndex;
+		newMgm.preOrderIndex = oldMgm.preOrderIndex;
+		newMgm.depth = oldMgm.depth;
+		newMgm.exports = oldMgm.exports;
+		newMgm.async = oldMgm.async;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {void}
+	 */
+	removeModuleAttributes(module) {
+		const mgm = this._getModuleGraphModule(module);
+		mgm.postOrderIndex = null;
+		mgm.preOrderIndex = null;
+		mgm.depth = null;
+		mgm.async = false;
+	}
+
+	/**
+	 * @returns {void}
+	 */
+	removeAllModuleAttributes() {
+		for (const mgm of this._moduleMap.values()) {
+			mgm.postOrderIndex = null;
+			mgm.preOrderIndex = null;
+			mgm.depth = null;
+			mgm.async = false;
+		}
+	}
+
+	/**
+	 * @param {Module} oldModule the old referencing module
+	 * @param {Module} newModule the new referencing module
+	 * @param {function(ModuleGraphConnection): boolean} filterConnection filter predicate for replacement
+	 * @returns {void}
+	 */
+	moveModuleConnections(oldModule, newModule, filterConnection) {
+		if (oldModule === newModule) return;
+		const oldMgm = this._getModuleGraphModule(oldModule);
+		const newMgm = this._getModuleGraphModule(newModule);
+		// Outgoing connections
+		const oldConnections = oldMgm.outgoingConnections;
+		if (oldConnections !== undefined) {
+			if (newMgm.outgoingConnections === undefined) {
+				newMgm.outgoingConnections = new SortableSet();
+			}
+			const newConnections = newMgm.outgoingConnections;
+			for (const connection of oldConnections) {
+				if (filterConnection(connection)) {
+					connection.originModule = newModule;
+					newConnections.add(connection);
+					oldConnections.delete(connection);
+				}
+			}
+		}
+		// Incoming connections
+		const oldConnections2 = oldMgm.incomingConnections;
+		const newConnections2 = newMgm.incomingConnections;
+		for (const connection of oldConnections2) {
+			if (filterConnection(connection)) {
+				connection.module = newModule;
+				newConnections2.add(connection);
+				oldConnections2.delete(connection);
+			}
+		}
+	}
+
+	/**
+	 * @param {Module} oldModule the old referencing module
+	 * @param {Module} newModule the new referencing module
+	 * @param {function(ModuleGraphConnection): boolean} filterConnection filter predicate for replacement
+	 * @returns {void}
+	 */
+	copyOutgoingModuleConnections(oldModule, newModule, filterConnection) {
+		if (oldModule === newModule) return;
+		const oldMgm = this._getModuleGraphModule(oldModule);
+		const newMgm = this._getModuleGraphModule(newModule);
+		// Outgoing connections
+		const oldConnections = oldMgm.outgoingConnections;
+		if (oldConnections !== undefined) {
+			if (newMgm.outgoingConnections === undefined) {
+				newMgm.outgoingConnections = new SortableSet();
+			}
+			const newConnections = newMgm.outgoingConnections;
+			for (const connection of oldConnections) {
+				if (filterConnection(connection)) {
+					const newConnection = connection.clone();
+					newConnection.originModule = newModule;
+					newConnections.add(newConnection);
+					if (newConnection.module !== undefined) {
+						const otherMgm = this._getModuleGraphModule(newConnection.module);
+						otherMgm.incomingConnections.add(newConnection);
+					}
+				}
+			}
+		}
+	}
+
+	/**
+	 * @param {Module} module the referenced module
+	 * @param {string} explanation an explanation why it's referenced
+	 * @returns {void}
+	 */
+	addExtraReason(module, explanation) {
+		const connections = this._getModuleGraphModule(module).incomingConnections;
+		connections.add(new ModuleGraphConnection(null, null, module, explanation));
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency to look for a referenced module
+	 * @returns {Module | null} the referenced module
+	 */
+	getResolvedModule(dependency) {
+		const connection = this.getConnection(dependency);
+		return connection !== undefined ? connection.resolvedModule : null;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency to look for a referenced module
+	 * @returns {ModuleGraphConnection | undefined} the connection
+	 */
+	getConnection(dependency) {
+		const connection = this._dependencyMap.get(dependency);
+		if (connection === undefined) {
+			const module = this.getParentModule(dependency);
+			if (module !== undefined) {
+				const mgm = this._getModuleGraphModule(module);
+				if (
+					mgm._unassignedConnections &&
+					mgm._unassignedConnections.length !== 0
+				) {
+					let foundConnection;
+					for (const connection of mgm._unassignedConnections) {
+						this._dependencyMap.set(
+							/** @type {Dependency} */ (connection.dependency),
+							connection
+						);
+						if (connection.dependency === dependency)
+							foundConnection = connection;
+					}
+					mgm._unassignedConnections.length = 0;
+					if (foundConnection !== undefined) {
+						return foundConnection;
+					}
+				}
+			}
+			this._dependencyMap.set(dependency, null);
+			return;
+		}
+		return connection === null ? undefined : connection;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency to look for a referenced module
+	 * @returns {Module | null} the referenced module
+	 */
+	getModule(dependency) {
+		const connection = this.getConnection(dependency);
+		return connection !== undefined ? connection.module : null;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency to look for a referencing module
+	 * @returns {Module | null} the referencing module
+	 */
+	getOrigin(dependency) {
+		const connection = this.getConnection(dependency);
+		return connection !== undefined ? connection.originModule : null;
+	}
+
+	/**
+	 * @param {Dependency} dependency the dependency to look for a referencing module
+	 * @returns {Module | null} the original referencing module
+	 */
+	getResolvedOrigin(dependency) {
+		const connection = this.getConnection(dependency);
+		return connection !== undefined ? connection.resolvedOriginModule : null;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {Iterable<ModuleGraphConnection>} reasons why a module is included
+	 */
+	getIncomingConnections(module) {
+		const connections = this._getModuleGraphModule(module).incomingConnections;
+		return connections;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {Iterable<ModuleGraphConnection>} list of outgoing connections
+	 */
+	getOutgoingConnections(module) {
+		const connections = this._getModuleGraphModule(module).outgoingConnections;
+		return connections === undefined ? EMPTY_SET : connections;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {readonly Map<Module | undefined | null, readonly ModuleGraphConnection[]>} reasons why a module is included, in a map by source module
+	 */
+	getIncomingConnectionsByOriginModule(module) {
+		const connections = this._getModuleGraphModule(module).incomingConnections;
+		return connections.getFromUnorderedCache(getConnectionsByOriginModule);
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {readonly Map<Module | undefined, readonly ModuleGraphConnection[]> | undefined} connections to modules, in a map by module
+	 */
+	getOutgoingConnectionsByModule(module) {
+		const connections = this._getModuleGraphModule(module).outgoingConnections;
+		return connections === undefined
+			? undefined
+			: connections.getFromUnorderedCache(getConnectionsByModule);
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {ModuleProfile | undefined} the module profile
+	 */
+	getProfile(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.profile;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {ModuleProfile | undefined} profile the module profile
+	 * @returns {void}
+	 */
+	setProfile(module, profile) {
+		const mgm = this._getModuleGraphModule(module);
+		mgm.profile = profile;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {Module | null | undefined} the issuer module
+	 */
+	getIssuer(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.issuer;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {Module | null} issuer the issuer module
+	 * @returns {void}
+	 */
+	setIssuer(module, issuer) {
+		const mgm = this._getModuleGraphModule(module);
+		mgm.issuer = issuer;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {Module | null} issuer the issuer module
+	 * @returns {void}
+	 */
+	setIssuerIfUnset(module, issuer) {
+		const mgm = this._getModuleGraphModule(module);
+		if (mgm.issuer === undefined) mgm.issuer = issuer;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {(string | OptimizationBailoutFunction)[]} optimization bailouts
+	 */
+	getOptimizationBailout(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.optimizationBailout;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {true | string[] | null} the provided exports
+	 */
+	getProvidedExports(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.exports.getProvidedExports();
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {string | string[]} exportName a name of an export
+	 * @returns {boolean | null} true, if the export is provided by the module.
+	 * null, if it's unknown.
+	 * false, if it's not provided.
+	 */
+	isExportProvided(module, exportName) {
+		const mgm = this._getModuleGraphModule(module);
+		const result = mgm.exports.isExportProvided(exportName);
+		return result === undefined ? null : result;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {ExportsInfo} info about the exports
+	 */
+	getExportsInfo(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.exports;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {string} exportName the export
+	 * @returns {ExportInfo} info about the export
+	 */
+	getExportInfo(module, exportName) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.exports.getExportInfo(exportName);
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {string} exportName the export
+	 * @returns {ExportInfo} info about the export (do not modify)
+	 */
+	getReadOnlyExportInfo(module, exportName) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.exports.getReadOnlyExportInfo(exportName);
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {RuntimeSpec} runtime the runtime
+	 * @returns {false | true | SortableSet<string> | null} the used exports
+	 * false: module is not used at all.
+	 * true: the module namespace/object export is used.
+	 * SortableSet<string>: these export names are used.
+	 * empty SortableSet<string>: module is used but no export.
+	 * null: unknown, worst case should be assumed.
+	 */
+	getUsedExports(module, runtime) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.exports.getUsedExports(runtime);
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {number | null} the index of the module
+	 */
+	getPreOrderIndex(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.preOrderIndex;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {number | null} the index of the module
+	 */
+	getPostOrderIndex(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.postOrderIndex;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {number} index the index of the module
+	 * @returns {void}
+	 */
+	setPreOrderIndex(module, index) {
+		const mgm = this._getModuleGraphModule(module);
+		mgm.preOrderIndex = index;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {number} index the index of the module
+	 * @returns {boolean} true, if the index was set
+	 */
+	setPreOrderIndexIfUnset(module, index) {
+		const mgm = this._getModuleGraphModule(module);
+		if (mgm.preOrderIndex === null) {
+			mgm.preOrderIndex = index;
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {number} index the index of the module
+	 * @returns {void}
+	 */
+	setPostOrderIndex(module, index) {
+		const mgm = this._getModuleGraphModule(module);
+		mgm.postOrderIndex = index;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {number} index the index of the module
+	 * @returns {boolean} true, if the index was set
+	 */
+	setPostOrderIndexIfUnset(module, index) {
+		const mgm = this._getModuleGraphModule(module);
+		if (mgm.postOrderIndex === null) {
+			mgm.postOrderIndex = index;
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {number | null} the depth of the module
+	 */
+	getDepth(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.depth;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {number} depth the depth of the module
+	 * @returns {void}
+	 */
+	setDepth(module, depth) {
+		const mgm = this._getModuleGraphModule(module);
+		mgm.depth = depth;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @param {number} depth the depth of the module
+	 * @returns {boolean} true, if the depth was set
+	 */
+	setDepthIfLower(module, depth) {
+		const mgm = this._getModuleGraphModule(module);
+		if (mgm.depth === null || mgm.depth > depth) {
+			mgm.depth = depth;
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {boolean} true, if the module is async
+	 */
+	isAsync(module) {
+		const mgm = this._getModuleGraphModule(module);
+		return mgm.async;
+	}
+
+	/**
+	 * @param {Module} module the module
+	 * @returns {void}
+	 */
+	setAsync(module) {
+		const mgm = this._getModuleGraphModule(module);
+		mgm.async = true;
+	}
+
+	/**
+	 * @param {any} thing any thing
+	 * @returns {object} metadata
+	 */
+	getMeta(thing) {
+		let meta = this._metaMap.get(thing);
+		if (meta === undefined) {
+			meta = Object.create(null);
+			this._metaMap.set(thing, /** @type {object} */ (meta));
+		}
+		return /** @type {object} */ (meta);
+	}
+
+	/**
+	 * @param {any} thing any thing
+	 * @returns {object | undefined} metadata
+	 */
+	getMetaIfExisting(thing) {
+		return this._metaMap.get(thing);
+	}
+
+	/**
+	 * @param {string=} cacheStage a persistent stage name for caching
+	 */
+	freeze(cacheStage) {
+		this._cache = new WeakTupleMap();
+		this._cacheStage = cacheStage;
+	}
+
+	unfreeze() {
+		this._cache = undefined;
+		this._cacheStage = undefined;
+	}
+
+	/**
+	 * @template {any[]} T
+	 * @template V
+	 * @param {(moduleGraph: ModuleGraph, ...args: T) => V} fn computer
+	 * @param {T} args arguments
+	 * @returns {V} computed value or cached
+	 */
+	cached(fn, ...args) {
+		if (this._cache === undefined) return fn(this, ...args);
+		return this._cache.provide(fn, ...args, () => fn(this, ...args));
+	}
+
+	/**
+	 * @param {Map<Module, WeakTupleMap<any, any>>} moduleMemCaches mem caches for modules for better caching
+	 */
+	setModuleMemCaches(moduleMemCaches) {
+		this._moduleMemCaches = moduleMemCaches;
+	}
+
+	/**
+	 * @param {Dependency} dependency dependency
+	 * @param {...any} args arguments, last argument is a function called with moduleGraph, dependency, ...args
+	 * @returns {any} computed value or cached
+	 */
+	dependencyCacheProvide(dependency, ...args) {
+		/** @type {(moduleGraph: ModuleGraph, dependency: Dependency, ...args: any[]) => any} */
+		const fn = args.pop();
+		if (this._moduleMemCaches && this._cacheStage) {
+			const memCache = this._moduleMemCaches.get(
+				/** @type {Module} */ (this.getParentModule(dependency))
+			);
+			if (memCache !== undefined) {
+				return memCache.provide(dependency, this._cacheStage, ...args, () =>
+					fn(this, dependency, ...args)
+				);
+			}
+		}
+		if (this._cache === undefined) return fn(this, dependency, ...args);
+		return this._cache.provide(dependency, ...args, () =>
+			fn(this, dependency, ...args)
+		);
+	}
+
+	// TODO remove in webpack 6
+	/**
+	 * @param {Module} module the module
+	 * @param {string} deprecateMessage message for the deprecation message
+	 * @param {string} deprecationCode code for the deprecation
+	 * @returns {ModuleGraph} the module graph
+	 */
+	static getModuleGraphForModule(module, deprecateMessage, deprecationCode) {
+		const fn = deprecateMap.get(deprecateMessage);
+		if (fn) return fn(module);
+		const newFn = util.deprecate(
+			/**
+			 * @param {Module} module the module
+			 * @returns {ModuleGraph} the module graph
+			 */
+			module => {
+				const moduleGraph = moduleGraphForModuleMap.get(module);
+				if (!moduleGraph)
+					throw new Error(
+						`${
+							deprecateMessage
+						}There was no ModuleGraph assigned to the Module for backward-compat (Use the new API)`
+					);
+				return moduleGraph;
+			},
+			`${deprecateMessage}: Use new ModuleGraph API`,
+			deprecationCode
+		);
+		deprecateMap.set(deprecateMessage, newFn);
+		return newFn(module);
+	}
+
+	// TODO remove in webpack 6
+	/**
+	 * @param {Module} module the module
+	 * @param {ModuleGraph} moduleGraph the module graph
+	 * @returns {void}
+	 */
+	static setModuleGraphForModule(module, moduleGraph) {
+		moduleGraphForModuleMap.set(module, moduleGraph);
+	}
+
+	// TODO remove in webpack 6
+	/**
+	 * @param {Module} module the module
+	 * @returns {void}
+	 */
+	static clearModuleGraphForModule(module) {
+		moduleGraphForModuleMap.delete(module);
+	}
+}
+
+// TODO remove in webpack 6
+/** @type {WeakMap<Module, ModuleGraph>} */
+const moduleGraphForModuleMap = new WeakMap();
+
+// TODO remove in webpack 6
+/** @type {Map<string, (module: Module) => ModuleGraph>} */
+const deprecateMap = new Map();
+
+module.exports = ModuleGraph;
+module.exports.ModuleGraphConnection = ModuleGraphConnection;
