docs: function (child) {
              var index = 0,
                  element;
  
              for (var i = 0; i < this.$parent.$children.length; i++) {
                  element = this.$parent.$children[i];
                  if (element === this) {
                      return ++index;
                  } else {
                      index++;
                  }
              }
              return index;
          }