code: private function parseDirectives($isConst)
      {
          $directives = [];
          while ($this->peek(Token::AT)) {
              $directives[] = $this->parseDirective($isConst);
          }
  
          return new NodeList($directives);
      }
docs: @param bool $isConst
  
  @return DirectiveNode[]|NodeList
  
  @throws SyntaxError