title: why the rxswift run only 1 times
body: <pre><code>Observable.of("A", "B", "C").subscribe{  print("test", $0)  } // run 4 times
  </code></pre>
  
  <p>--- output:</p>
  
  <blockquote>
    <p>test next(A) test next(B) test next(C) test completed</p>
  </blockquote>
  
  <p>but the code:  why run only 1  times </p>
  
  <pre><code>  Observable.of("A", "B", "C").subscribe{   print("test")   }  
  </code></pre>
  
  <p>--- output</p>
  
  <blockquote>
    <p>test</p>
  </blockquote>