Index: node_modules/d3-transition/src/transition/ease.js
===================================================================
--- node_modules/d3-transition/src/transition/ease.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-transition/src/transition/ease.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,16 @@
+import {get, set} from "./schedule.js";
+
+function easeConstant(id, value) {
+  if (typeof value !== "function") throw new Error;
+  return function() {
+    set(this, id).ease = value;
+  };
+}
+
+export default function(value) {
+  var id = this._id;
+
+  return arguments.length
+      ? this.each(easeConstant(id, value))
+      : get(this.node(), id).ease;
+}