title: Immutable JS update all object in map
body: <p>I have this map:</p>
  
  <pre><code>map1:{
      x: {...}
      y: {...}
      h: {...}
      j: {...}
      k: {...}
  }
  </code></pre>
  
  <p>How can I update a common property, for example "selected" for all the objects in the map, and fastest as possible for react redux js with immutable js?</p>
  
  <p>Thanks.</p>