Interpret2() private method

See http://stackoverflow.com/questions/160118/static-and-instance-methods-with-the-same-name.
private Interpret2 ( IList tokens ) : FormulaTree
tokens IList
return Catrobat.IDE.Core.Models.Formulas.Tree.FormulaTree
        public static FormulaTree Interpret(IList<IFormulaToken> tokens, out ParsingError parsingError)
        {
            // TODO: split to InterpretNumber and InterpretLogic
            //var sw = new Stopwatch();
            //sw.Start();

            // interpret tokens
            var instance = new FormulaInterpreter();
            var result = instance.Interpret2(tokens);
            parsingError = instance.ParsingError;

            //sw.Stop();
            // Debug.WriteLine("Interpreter.Interpret needed " + sw.ElapsedMilliseconds + "ms");

            return result;
        }
        public static FormulaTree Interpret(IList <IFormulaToken> tokens, out ParsingError parsingError)
        {
            // TODO: split to InterpretNumber and InterpretLogic
            //var sw = new Stopwatch();
            //sw.Start();

            // interpret tokens
            var instance = new FormulaInterpreter();
            var result   = instance.Interpret2(tokens);

            parsingError = instance.ParsingError;

            //sw.Stop();
            // Debug.WriteLine("Interpreter.Interpret needed " + sw.ElapsedMilliseconds + "ms");

            return(result);
        }