@abc.abstractmethod<EOL><INDENT>def set_agent(self, agent_id):<DEDENT>
pass<EOL>
Sets the agent.

        :param agent_id: the new agent
        :type agent_id: ``osid.id.Id``
        :raise: ``InvalidArgument`` -- ``agent_id`` is invalid
        :raise: ``NoAccess`` -- ``Metadata.isReadOnly()`` is ``true``
        :raise: ``NullArgument`` -- ``agent_id`` is ``null``

        *compliance: mandatory -- This method must be implemented.*