title: Is the diamond operator <> equivalent to <?>
body: <p>I found in the <code>util.TreeSet</code> class that one of the constructor is calling another constructor with a new <code>TreeMap</code> with empty generic type. </p>
  
  <pre><code>  public TreeSet(Comparator&lt;? super E&gt; comparator) {
           this(new TreeMap&lt;&gt;(comparator));
    }
  </code></pre>
  
  <p>What does <code>new TreeMap&lt;&gt;</code> mean ? is that equivalent to <code>new TreeMap&lt;?&gt;</code> ?</p>