private static TokenListBuilder<ParserTokenType> Token(ParserTokenType type, string value)
 {
     var builder = new TokenListBuilder<ParserTokenType>();
     return builder.Token(type, value);
 }
        ////[Fact]
        ////public void UseStatement()
        ////{
        ////    this.TestLexer(
        ////        "use appx",
        ////        Token(LexerTokenType.UseKeyword, "use")
        ////            .Token(LexerTokenType.Whitespace, " ")
        ////            .Token(LexerTokenType.Identifier, "appx")
        ////        );
        ////}

        private static TokenListBuilder <LexerTokenType> Token(LexerTokenType type, string value)
        {
            var builder = new TokenListBuilder <LexerTokenType>();

            return(builder.Token(type, value));
        }