Start the worker by invoking the :meth:`create_server` method.

async def worker_start(self, worker, exc=None):
        '''Start the worker by invoking the :meth:`create_server` method.
        '''
        if not exc and self.name not in worker.servers:
            servers = await self.binds(worker, worker.sockets)
            for server in servers.values():
                server.event('stop').bind(lambda _, **kw: worker.stop())