docs: function broadcast(messageName, data) {
              var i, len, instance, messages;
              for (i = 0, len = instances.length; i < len; ++i) {
                  instance = instances[i];
                  if (!instance) {
                      continue;
                  }
                  messages = instance.messages || [];
  
                  if (util.inArray(messageName, messages) !== -1) {
                      if (util.isFn(instance.onmessage)) {
                          instance.onmessage.call(instance, messageName, data);
                      }
                  }
              }
          }