ed operations and handling
controls.

<h3>Extended Operations</h3>
<p>
This package defines the interface <code>ExtendedRequest</code>
to represent the argument to an extended operation,
and the interface <code>ExtendedResponse</code> to represent the result
of the extended operation.
An extended response is always paired with an extended request
but not necessarily vice versa. That is, you can have an extended request
that has no corresponding extended response.
<p>
An application typically does not deal d