public function getLexer()
    {
        @trigger_error(sprintf('The %s() method is deprecated since version 1.25 and will be removed in 2.0.', __FUNCTION__), E_USER_DEPRECATED);

        if (null === $this->lexer) {
            $this->lexer = new Twig_Lexer($this);
        }

        return $this->lexer;
    }