function processRecursively(node, key)
        {
            for (var i = 0, child; child = node.children[i]; ++i) {
                var childKey = key + "#" + child.name;
                callback(child, childKey);
                processRecursively(child, childKey);
            }
        }
@param {!WebInspector.DataGridNode} node
@param {string} key