code: func (s *Stream) SetChannelMask(mask int) error {
  	return convertToError(C.Pm_SetChannelMask(unsafe.Pointer(s.pmStream), C.int(mask)))
  }
docs: // SetChannelMask filters incoming stream based on channel.
  // In order to filter from more than a single channel, or multiple channels.
  // s.SetChannelMask(Channel(1) | Channel(10)) will both filter input
  // from channel 1 and 10.