code: public static Collection<Channel> toChannels(
  			Collection<Channel.Builder> channelBuilders) {
  		Collection<Channel> channels = new HashSet<Channel>();
  		for (Channel.Builder builder : channelBuilders) {
  			channels.add(builder.build());
  		}
  		return Collections.unmodifiableCollection(channels);
  	}
docs: Returns a list of {@link Channel} built from the list of
  {@link Channel.Builder}s
  
  @param channelBuilders
  - list of Channel.Builder to be built.
  @return Collection of {@link Channel} built from the channelBuilders