function onDocumentAvailable(error, root)
        {
            if (!error)
                this._setDocument(root);

            for (var i = 0; i < this._pendingDocumentRequestCallbacks.length; ++i) {
                var callback = this._pendingDocumentRequestCallbacks[i];
                if (callback)
                    callback(this._document);
            }
            delete this._pendingDocumentRequestCallbacks;
        }
@this {WebInspector.DOMModel}
@param {?Protocol.Error} error
@param {!DOMAgent.Node} root