{@inheritDoc}
@implSpec This implementation calls <tt>entrySet().clear()</tt>.
<p>Note that this implementation throws an <tt>UnsupportedOperationException</tt> if the <tt>entrySet</tt> does not support the <tt>clear</tt> operation.
@throws UnsupportedOperationException {@inheritDoc}
See Implementation
{@inheritDoc}
@implSpec This implementation calls <tt>entrySet().clear()</tt>.
<p>Note that this implementation throws an <tt>UnsupportedOperationException</tt> if the <tt>entrySet</tt> does not support the <tt>clear</tt> operation.
@throws UnsupportedOperationException {@inheritDoc}