raise(pos, message) {
            const loc = Parser.acorn.getLineInfo(this.input, pos);
            const err = new SyntaxError(message);

            err.index = pos;
            err.lineNumber = loc.line;
            err.column = loc.column + 1; // acorn uses 0-based columns
            throw err;
        }
Overwrites the default raise method to throw Esprima-style errors.
@param {int} pos The position of the error.
@param {string} message The error message.
@throws {SyntaxError} A syntax error.
@returns {void}