code: def iter(self, *, encoding=None, decoder=None):
          
          return _IterHelper(self,
                             is_active=lambda r: not r._queue.exhausted,
                             encoding=encoding,
                             decoder=decoder)
docs: Returns async iterator.
  
          Usage example:
  
          >>> async for ch, msg in mpsc.iter():
          ...     print(ch, msg)