ce in java.lang">ClassCastException</a></code> - if the key is of an inappropriate type for this map (optionally thrown by the underlying
 <code>Map</code>).</dd>
<dd><code><a href="https://docs.oracle.com/javase/7/docs/api/java/lang/NullPointerException.html?is-external=true" title="class or interface in java.lang">NullPointerException</a></code> - if context is <code>null</code>, or if the key is null and this map does not permit null
 keys (the latter is optionally thrown by the underlying <code>Map</cod