@abc.abstractmethod<EOL><INDENT>def set_effective_agent_id(self, agent_id):<DEDENT>
pass<EOL>
Sets the effective agent ``Id`` to indicate acting on behalf of.

        :param agent_id: an agent ``Id``
        :type agent_id: ``osid.id.Id``
        :raise: ``NullArgument`` -- ``agent_id`` is ``null``

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