private function next($includeWhiteSpace = false)
    {
        for ($i = $this->tokenPos; $i < $this->tokensCount; $i++) {
            $this->tokenPos++;
            if (($includeWhiteSpace === false && $this->tokens[$i][0] === T_WHITESPACE) || $this->tokens[$i][0] === T_COMMENT) {
                continue;
            }

            return $this->tokens[$i];
        }

        return null;
    }