Index: node_modules/d3-selection/src/selection/insert.js
===================================================================
--- node_modules/d3-selection/src/selection/insert.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-selection/src/selection/insert.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,14 @@
+import creator from "../creator.js";
+import selector from "../selector.js";
+
+function constantNull() {
+  return null;
+}
+
+export default function(name, before) {
+  var create = typeof name === "function" ? name : creator(name),
+      select = before == null ? constantNull : typeof before === "function" ? before : selector(before);
+  return this.select(function() {
+    return this.insertBefore(create.apply(this, arguments), select.apply(this, arguments) || null);
+  });
+}