function didPopulateChildren(nodePosition, callback)
        {
            var node = /** @type {?WebInspector.HeapSnapshotGridNode} */ (this.childForPosition(nodePosition));
            callback(node ? [this, node] : []);
        }
@this {WebInspector.HeapSnapshotConstructorNode}
@param {number} nodePosition
@param {function(!Array<!WebInspector.HeapSnapshotGridNode>)} callback