So siehts ganz gut aus !

node_modules/babel-runtime/helpers/instanceof.js

@@ -0,0 +1,21 @@
+"use strict";
+
+exports.__esModule = true;
+
+var _hasInstance = require("../core-js/symbol/has-instance");
+
+var _hasInstance2 = _interopRequireDefault(_hasInstance);
+
+var _symbol = require("../core-js/symbol");
+
+var _symbol2 = _interopRequireDefault(_symbol);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+exports.default = function (left, right) {
+  if (right != null && typeof _symbol2.default !== "undefined" && right[_hasInstance2.default]) {
+    return right[_hasInstance2.default](left);
+  } else {
+    return left instanceof right;
+  }
+};