protected function createLexicalVariables() {
    if (!$this->hasLexicalVariables()) {
      $this->lexicalUse = Token::_use();
      $this->lexicalOpenParen = Token::openParen();
      $this->lexicalVariables = new CommaListNode();
      $this->lexicalCloseParen = Token::closeParen();
      $this->closeParen->after([
        Token::space(),
        $this->lexicalUse,
        Token::space(),
        $this->lexicalOpenParen,
        $this->lexicalVariables,
        $this->lexicalCloseParen,
      ]);
    }
  }