code: func NewChannelService(ctx contextAPI.Client, membership fab.ChannelMembership, channelID string, opts ...coptions.Opt) (*ChannelService, error) {
  	logger.Debug("Creating new dynamic discovery service")
  	s := &ChannelService{
  		channelID:  channelID,
  		membership: membership,
  	}
  	s.service = newService(ctx.EndpointConfig(), s.queryPeers, opts...)
  	err := s.service.initialize(ctx)
  	if err != nil {
  		return nil, err
  	}
  
  	return s, nil
  }
docs: // NewChannelService creates a Discovery Service to query the list of member peers on a given channel.