title: Advanced example of rxjs5 flattening
body: <p>I have similar data structure to this:</p>
  
  <pre><code>let userInfo =  [
        {
         id: 'id1',
         users: [
         {
          name: 'userName1',
          job: 'userJob',
         },
         {
          name: 'userName2',
          job: 'userJob',
         }
        ]
       },
        {
         id: 'id2',
         users: [
         {
          name: 'userName3',
          job: 'userJob',
         },
         {
           name: 'userName4',
          job: 'userJob',
         }
        ]
       }
      ]
  </code></pre>
  
  <p>Users are 
  I expected new flattened user stream with RxJS5:</p>
  
  <pre><code>    {
       parent: id,        // parent id, where users[] come from...
       name: 'userName'
       job: 'userJob'
      }
  </code></pre>
  
  <p>What is the clean functional way to archive this? Thank you...</p>