code: def pave_event_space(fn=pair):
      
      global _event_space
      event_space = next(_event_space)
  
      @_ensure_seeders_list
      def p(seeders, delegator_factory, *args, **kwargs):
          return fn(seeders + [per_event_source_id(event_space)],
                    delegator_factory, *args, event_space=event_space, **kwargs)
      return p
docs: :return:
          a pair producer that ensures the seeder and delegator share the same event space.