@abc.abstractmethod<EOL><INDENT>def get_agent_query(self):<DEDENT>
return<EOL>
Gets the query for an agent.

        :return: the agent query
        :rtype: ``osid.authentication.AgentQuery``
        :raise: ``Unimplemented`` -- ``supports_agent_query()`` is ``false``

        *compliance: optional -- This method must be implemented if
        ``supports_agent_query()`` is ``true``.*