Spatie\Php7to5\Exceptions\InvalidParameter::directoryIsRequired PHP Method

    public static function directoryIsRequired()
    {
        return new static('A directory must be specified');
    }

 /**
  * @param string $destinationDirectory
  *
  * @throws \Spatie\Php7to5\Exceptions\InvalidParameter
  */
 public function savePhp5FilesTo($destinationDirectory)
 {
     if ($destinationDirectory === '') {
         throw InvalidParameter::directoryIsRequired();
     }
     $this->copyDirectory($this->sourceDirectory, $destinationDirectory);
 }