public static function create(ExpressionNode $array, ExpressionNode $key) {
    $node = new static();
    /** @var Node $array */
    $node->addChild($array, 'array');
    $node->addChild(Token::openBracket());
    /** @var Node $key */
    $node->addChild($key, 'key');
    $node->addChild(Token::closeBracket());
    return $node;
  }