private static IEnumerable <IPublishedContent> ItemsByXPath(XPathExpression xpath, XPathVariable[] vars,
                                                                    IPublishedCache cache)
        {
            var doc = cache.GetByXPath(xpath, vars);

            return(doc);
        }
 private static IEnumerable <IPublishedContent> ItemsByXPath(XPathExpression xpath, XPathVariable[] vars, IPublishedCache?cache)
 => cache?.GetByXPath(xpath, vars) ?? Array.Empty <IPublishedContent>();