def get_effective_agent_id(self):
if self.has_effective_agent():<EOL><INDENT>return self._effective_agent_id<EOL><DEDENT>else:<EOL><INDENT>raise errors.IllegalState()<EOL><DEDENT>
Gets the effective ``Agent Id`` for this proxy.

        return: (osid.id.Id) - the effective agent ``Id``
        raise:  IllegalState - ``has_effective_agent()`` is ``false``
        *compliance: mandatory -- This method must be implemented.*