var XPath = { cache: null, reset: function () { this.cache = {__proto__: null}; }, get: function (context, expr, type) { var cache = this.cache, evaluator; if (expr in cache) { evaluator = cache[expr]; } else { evaluator = cache[expr] = XPathEvaluator().createExpression(expr, null); } return evaluator.evaluate(context, type, null); }, has: function (context, expr) { return this.get(context, expr,