title: Concat vs ConcatArray RxJava
body: <p>Is there any difference between concat and concatArray in RxJava2 except of the number of ObservableSources?</p>
  
  <pre><code>Observable.concat(observable1, observable2)
  
  Observable.concatArray(observable1, observable2, observable3, observable4)
  </code></pre>
  
  <p>The maximum number of ObservableSources in </p>
  
  <blockquote>
    <p><code>concat(ObservableSource&lt;? extends T&gt; source1, ObservableSource&lt;? extends T&gt; source2, ObservableSource&lt;? extends T&gt; source3, ObservableSource&lt;? extends T&gt; sourc4)</code>                                                                              </p>
  </blockquote>
  
  <p>is 4, but in </p>
  
  <blockquote>
    <p><code>concatArray(ObservableSource&lt;? extends T&gt;... sources)</code></p>
  </blockquote>
  
  <p>Is this the only difference between those two?</p>