internal static IPromise <GenerateGrammarResponse> GenerateGrammar(string grammarId)
 {
     return(!GrammarList.ContainsKey(grammarId)
         ? Promise <GenerateGrammarResponse> .Rejected(new ApplicationException("Generate grammar request error:\nRequested grammar not found."))
         : WebAPI.GenerateGrammar(GrammarList[grammarId])
            .Then(_ => {
         UpdateUserInfo();
         return _;
     }));
 }