So siehts ganz gut aus !

node_modules/es5-ext/object/is-thenable.js

@@ -0,0 +1,8 @@
+"use strict";
+
+var isCallable = require("./is-callable")
+  , isObject   = require("./is-object");
+
+module.exports = function (value) {
+	return isObject(value) && isCallable(value.then);
+};