docs: function() {
      source.removeListener('record', onRecord);
      dest.removeListener('drain', onDrain);
  
      source.removeListener('end', onEnd);
      source.removeListener('close', onClose);
  
      source.removeListener('error', onError);
      dest.removeListener('error', onError);
  
      source.removeListener('end', cleanup);
      source.removeListener('close', cleanup);
  
      dest.removeListener('end', cleanup);
      dest.removeListener('close', cleanup);
    }