protected static IParseTree AntlrParse(string expression)
{
var inputStream = new AntlrInputStream(expression);
var lexer = new ExpressionLexer(inputStream);
lexer.RemoveErrorListeners();
var tokenStream = new CommonTokenStream(lexer);
var parser = new ExpressionParser(tokenStream);
parser.RemoveErrorListeners();
parser.AddErrorListener(ParserErrorListener.Instance);
parser.BuildParseTree = true;
return(parser.file()?.expression());
}