code: def add_channel(channel: EFBChannel):
      
      global master, slaves
      if isinstance(channel, EFBChannel):
          if channel.channel_type == ChannelType.Slave:
              slaves[channel.channel_id] = channel
          else:
              master = channel
      else:
          raise TypeError("Channel instance is expected")
docs: Register the channel with the coordinator.
  
      Args:
          channel (EFBChannel): Channel to register