code: private function parseDirectiveLocations()
      {
          // Optional leading pipe
          $this->skip(Token::PIPE);
          $locations = [];
          do {
              $locations[] = $this->parseDirectiveLocation();
          } while ($this->skip(Token::PIPE));
  
          return $locations;
      }
docs: @return NameNode[]
  
  @throws SyntaxError