code: 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;
      }
docs: Gets the Lexer instance.
  
  @return Twig_LexerInterface
  
  @deprecated since 1.25 (to be removed in 2.0)