code: private function getChunksFromUnit(\DOMElement $unit): array
      {
          $chunks = explode('.', $unit->getAttribute('id'));
  
          // Handle keys with dots
          if (preg_match('/tl_layout\.[a-z]+\.css\./', $unit->getAttribute('id'))) {
              $chunks = [$chunks[0], $chunks[1].'.'.$chunks[2], $chunks[3]];
          }
  
          return $chunks;
      }
docs: Splits the ID attribute and returns the chunks.