e the return value.
 </p>

 <p>
 Just as in <a href="https://docs.oracle.com/javase/7/docs/api/java/util/Map.html?is-external=true#get-java.lang.Object-" title="class or interface in java.util"><code>Map.get(java.lang.Object)</code></a>, just because <code>null</code> is returned doesn't mean there is no mapping for
 the key; it's also possible that the <code>Map</code> explicitly maps the key to <code>null</code>.
 </p></div>
<dl>
<dt><span class="overrideSpecifyLabel">Specified by:</span></dt>
<dd><code><