title: ConcurrentHashMap.newKeySet() vs Collections.newSetFromMap()
body: <p>Java 8 introduced new way to obtain a concurrent <code>Set</code> implementation</p>
  
  <pre><code>// Pre-Java-8 way to create a concurrent set
  Set&lt;String&gt; oldStyle = Collections.newSetFromMap(new ConcurrentHashMap&lt;&gt;());
  // New method in Java 8
  Set&lt;String&gt; newStyle = ConcurrentHashMap.newKeySet();
  </code></pre>
  
  <p>Is there any reason to prefer new method?</p>
  
  <p>Any advantages/disadvantages?</p>