title: How we can mix streams in dart?
body: <p>Let Two Stream deliver two different types of data.
  I want a one stream from those two stream that combine the data and wrap in data class and delivers it.</p>
  
  <p>Example:</p>
  
  <pre><code>Stream&lt;String&gt; stream1;
  Stream&lt;String&gt; stream2;
  
  class Data{
      String s1;
      String s2;
      Data(this.s1,this.s2);
  }
  </code></pre>