code: def close(self):
          
          for recv in self._receivers[:]:
              self.remove(recv)
          self._latch.close()
docs: Remove the select's notifier function from each registered receiver,
          mark the associated latch as closed, and cause any thread currently
          sleeping in :meth:`get` to be woken with
          :class:`mitogen.core.LatchError`.
  
          This is necessary to prevent memory leaks in long-running receivers. It
          is called automatically when the Python :keyword:`with` statement is
          used.