Spawn *n* agents to the managed environment. This is a convenience
        function so that one does not have to repeatedly make connections to
        the environment to spawn multiple agents with the same parameters.

        See :py:meth:`~creamas.mp.EnvManager.spawn` for details.

async def spawn_n(self, agent_cls, n, *args, **kwargs):
        '''Spawn *n* agents to the managed environment. This is a convenience
        function so that one does not have to repeatedly make connections to
        the environment to spawn multiple agents with the same parameters.

        See :py:meth:`~creamas.mp.EnvManager.spawn` for details.
        '''
        rets = []
        for _ in range(n):
            ret = await self.spawn(agent_cls, *args, **kwargs)
            rets.append(ret)
        return rets