# File lib/travis/client/listener.rb, line 99
      def subscribe(*entities)
        entities = entities.map do |entity|
          entity = entity.pusher_entity while entity.respond_to? :pusher_entity
          @channels.concat(entity.pusher_channels)
          entity
        end

        yield entities.any? ? EntityListener.new(self, entities) : self if block_given?
      end