Index: node_modules/d3-array/src/pairs.js
===================================================================
--- node_modules/d3-array/src/pairs.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-array/src/pairs.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,15 @@
+export default function pairs(values, pairof = pair) {
+  const pairs = [];
+  let previous;
+  let first = false;
+  for (const value of values) {
+    if (first) pairs.push(pairof(previous, value));
+    previous = value;
+    first = true;
+  }
+  return pairs;
+}
+
+export function pair(a, b) {
+  return [a, b];
+}