public IEnumerable <HtmlTag> BuildStylesheetTags(IEnumerable <string> stylesheets) { var results = find(stylesheets); if (results.Any(x => x.Asset == null)) { throw new MissingAssetException("Requested stylesheets(s) {0} cannot be found".ToFormat(Result.MissingListDescription(results))); } return(_inner.BuildStylesheetTags(stylesheets)); }