/**
  * This function sets the output file.
  *
  * @author David Pauli <*****@*****.**>
  * @param String $filename The filename of the new output file with path on the server.
  * @since 0.1.2
  */
 public static function setOutputFile($filename)
 {
     if (InputValidator::isEmpty($filename)) {
         return;
     }
     self::$OUTPUT_FILE = $filename;
 }