lib/Ext/data/NodeStore.js
function(node1, node2) {
        // A shortcut for siblings
        if (node1.parentNode === node2.parentNode) {
            return (node1.data.index < node2.data.index) ? -1 : 1;
        }

        // @NOTE: with the following algorithm we can only go 80 levels deep in the tree
        // and each node can contain 10000 direct children max
        var weight1 = 0,
            weight2 = 0,
            parent1 = node1,
            parent2 = node2;

        while (parent1) {
            weight1 += (Math.pow(10, (parent1.data.depth+1) * -4) * (parent1.data.index+1));
            parent1 = parent1.parentNode;
        }
        while (parent2) {
            weight2 += (Math.pow(10, (parent2.data.depth+1) * -4) * (parent2.data.index+1));
            parent2 = parent2.parentNode;
        }

        if (weight1 > weight2) {
            return 1;
        } else if (weight1 < weight2) {
            return -1;
        }
        return (node1.data.index > node2.data.index) ? 1 : -1;
    }
function(node1, node2) {
        // A shortcut for siblings
        if (node1.parentNode === node2.parentNode) {
            return (node1.data.index < node2.data.index) ? -1 : 1;
        }

        // @NOTE: with the following algorithm we can only go 80 levels deep in the tree
        // and each node can contain 10000 direct children max
        var weight1 = 0,
            weight2 = 0,
            parent1 = node1,
            parent2 = node2;

        while (parent1) {
            weight1 += (Math.pow(10, (parent1.data.depth+1) * -4) * (parent1.data.index+1));
            parent1 = parent1.parentNode;
        }
        while (parent2) {
            weight2 += (Math.pow(10, (parent2.data.depth+1) * -4) * (parent2.data.index+1));
            parent2 = parent2.parentNode;
        }

        if (weight1 > weight2) {
            return 1;
        } else if (weight1 < weight2) {
            return -1;
        }
        return (node1.data.index > node2.data.index) ? 1 : -1;
    }
This is a custom tree sorting algorithm. It uses the index property on each node to determine
how to sort siblings. It uses the depth property plus the index to create a weight for each node.
This weight algorithm has the limitation of not being able to go more then 80 levels in depth, or
more then 10k nodes per parent. The end result is a flat collection being correctly sorted based
on this one single sort function.
@param {Ext.data.NodeInterface} node1
@param {Ext.data.NodeInterface} node2
@return {Number}
@private