How to declare a Map containing certain properties with flowtype & immutable.js
<p>Given a website object created like this </p>

<pre><code>import {Map} from 'immutable' 
const website = new Map({name: 'My Website', url: 'http://www.myw.fr'})
</code></pre>

<p>How could I declare a websiteType which would be a map containing exactly the given properties.
I know I can do:</p>

<pre><code>declare type websiteType = Map&lt;string,string&gt;
</code></pre>

<p>But I would like to be more specific, and declare a map that must contain the properties <code>name</code> and <code>url</code> of type <code>string</code>.</p>

<p>Is it even possible?</p>