private function _sysGetTempDir($create = true)
  {
    if (is_null($this->_systemTempDirectory) && $create) {
      $sysTmpDir = rtrim(sys_get_temp_dir(), "\\/");

      do {
        $name = $sysTmpDir . "/" . uniqid("fs", true);
      } while (file_exists($name));

      mkdir($name, 0777);
      $this->_systemTempDirectory = $name;
    }
    return $this->_systemTempDirectory;
  }