* Checks document order of two siblings * @param {Element} a * @param {Element} b * @returns {Number} Returns less than 0 if a precedes b, greater

* Recursively sort a tree of comments using the comp comparator.

* Recursively sort a tree of comments using the comp comparator.

* Recursively sort a tree of comments using the comp comparator.

* Description * @method add * @param {} a * @param {} b * @return sum