Index: node_modules/d3-array/src/cross.js
===================================================================
--- node_modules/d3-array/src/cross.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-array/src/cross.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,33 @@
+function length(array) {
+  return array.length | 0;
+}
+
+function empty(length) {
+  return !(length > 0);
+}
+
+function arrayify(values) {
+  return typeof values !== "object" || "length" in values ? values : Array.from(values);
+}
+
+function reducer(reduce) {
+  return values => reduce(...values);
+}
+
+export default function cross(...values) {
+  const reduce = typeof values[values.length - 1] === "function" && reducer(values.pop());
+  values = values.map(arrayify);
+  const lengths = values.map(length);
+  const j = values.length - 1;
+  const index = new Array(j + 1).fill(0);
+  const product = [];
+  if (j < 0 || lengths.some(empty)) return product;
+  while (true) {
+    product.push(index.map((j, i) => values[i][j]));
+    let i = j;
+    while (++index[i] === lengths[i]) {
+      if (i === 0) return reduce ? product.map(reduce) : product;
+      index[i--] = 0;
+    }
+  }
+}