code: def pack_pipeline(self, commands):
          '''Packs pipeline commands into bytes.'''
          return b''.join(
              starmap(lambda *args: b''.join(self._pack_command(args)),
                      (a for a, _ in commands))f pack_pipeline(self, commands):
          '''Packs pipeline commands into bytes.'''
          return b''.join(
              starmap(lambda *args: b''.join(self._pack_command(args)),
                      (a for a, _ in commands)))
docs: Packs pipeline commands into bytes.