def get_taking_agent_query(self):
raise errors.Unimplemented()<EOL>
Gets the query for an agent.

        Multiple retrievals produce a nested ``OR`` term.

        return: (osid.authentication.AgentQuery) - the agent query
        raise:  Unimplemented - ``supports_taking_agent_query()`` is
                ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_taking_agent_query()`` is ``true``.*