title: Is there a Map implementation with the same contracts as the ECMAScript 6 Map draft?
body: <p>I wonder If there is an implementation of <code>Map</code> available with the same contract as the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map" rel="nofollow noreferrer">ECMAScript 6 draft</a>, such that could be used as a fallback for Browsers not supporting it? I know there are some implementations, e.g. from <a href="https://stackoverflow.com/a/383540/695457">this SO answer</a> or <a href="https://github.com/flesler/hashmap" rel="nofollow noreferrer">from here</a>, but they have different contracts so it would need to be manually adjusted.</p>