@abc.abstractmethod<EOL><INDENT>def search_among_agents(self, agent_ids):<DEDENT>
pass<EOL>
Execute this search among the given list of agents.

        :param agent_ids: list of agents
        :type agent_ids: ``osid.id.IdList``
        :raise: ``NullArgument`` -- ``agent_ids`` is ``null``

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