public void TestFoo()
        {
            const string input = @"
            module foo

            public class bar
            {
            public meth(const arg : int) : bool => abc <- 100
            }
            ";

            var parser = new MuteScriptParser();
            var lexer = new MuteGrammarLexer(new Antlr4.Runtime.AntlrInputStream(input));
            var muteParser = new MuteGrammarParser(new Antlr4.Runtime.UnbufferedTokenStream(lexer));

            var cmp = parser.VisitCompileUnit(muteParser.compileUnit());
            Console.WriteLine(cmp.ToString());
        }