code: private function createZip($pFilename)
      {
          // Create new ZIP file and open it for writing
          $zip = new ZipArchive();
  
          if (file_exists($pFilename)) {
              unlink($pFilename);
          }
          // Try opening the ZIP file
          if ($zip->open($pFilename, ZipArchive::OVERWRITE) !== true) {
              if ($zip->open($pFilename, ZipArchive::CREATE) !== true) {
                  throw new WriterException("Could not open $pFilename for writing.");
              }
          }
  
          return $zip;
      }
docs: Create zip object.
  
  @param string $pFilename
  
  @throws WriterException
  
  @return ZipArchive