docs: function(channel) {
        if (!channels[channel]) return;
  
        var args = [].slice.call(arguments, 1),
            subscription;
  
        for (var i = 0; i < channels[channel].length; i++) {
          subscription = channels[channel][i];
          subscription.fn.apply(subscription.context, args);
          if (subscription.once) {
            Backbone.Mediator.unsubscribe(channel, subscription.fn, subscription.context);
            i--;
          }
        }
      }