title: CompletableFuture, supplyAsync() and thenApply()
body: <p>Need to confirm something. The following code:</p>
  
  <pre><code>CompletableFuture
      .supplyAsync(() -&gt; {return doSomethingAndReturnA();})
      .thenApply(a -&gt; convertToB(a));
  </code></pre>
  
  <p>would be the same as:</p>
  
  <pre><code>CompletableFuture
      .supplyAsync(() -&gt; {
          A a = doSomethingAndReturnA();
          convertToB(a);
   });
  </code></pre>
  
  <p>Right? </p>
  
  <p>Furthermore, another two questions following as for "is there any reason why we would use <code>thenApply</code>?"</p>
  
  <p>1) having big code for conversion? </p>
  
  <p><strong>or</strong></p>
  
  <p>2)  need to reuse the lambda block in other places?</p>