Index: node_modules/d3-zoom/src/event.js
===================================================================
--- node_modules/d3-zoom/src/event.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-zoom/src/event.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,14 @@
+export default function ZoomEvent(type, {
+  sourceEvent,
+  target,
+  transform,
+  dispatch
+}) {
+  Object.defineProperties(this, {
+    type: {value: type, enumerable: true, configurable: true},
+    sourceEvent: {value: sourceEvent, enumerable: true, configurable: true},
+    target: {value: target, enumerable: true, configurable: true},
+    transform: {value: transform, enumerable: true, configurable: true},
+    _: {value: dispatch}
+  });
+}