code: def close(self):
          " Close pipe fds. "
          os.close(self._r)
          os.close(self._w)
          self._r = None
          self._w = Nonf close(self):
          " Close pipe fds. "
          os.close(self._r)
          os.close(self._w)
          self._r = None
          self._w = None
docs: Close pipe fds.