public function getProperty($key, $notifyWarnings = true)
  {
    if (!(isset($this->configSettings[$key])) && $notifyWarnings) {
      echo 'MB_Configuration->getProperty() - Warning: "' . $key . '" not defined.', PHP_EOL;
      $callers = debug_backtrace();
      echo '- Called from: ' . $callers[1]['function'], PHP_EOL;
      return false;
    } elseif (!(isset($this->configSettings[$key]))) {
      return false;
    }
    return $this->configSettings[$key];
  }