code: public function transform(string $target)
      {
          if ($this->filesystem->isFile($target)) {
              $this->doTransform($target);
  
              return;
          }
  
          $files = $this->filesystem->allFiles($target);
  
          array_walk($files, function (SplFileInfo $file) {
              $this->doTransform($file->getRealPath());
          });
      }
docs: Transform a file or directory recursively.
  
  @todo Skip non-php files.
  
  @param string $target Path to the target file or directory.
  
  @return void