private function getSimpleValue($value)
  {
    if ($value instanceof Google_Model) {
      return $value->toSimpleObject();
    } else if (is_array($value)) {
      $return = array();
      foreach ($value as $key => $a_value) {
        $a_value = $this->getSimpleValue($a_value);
        if ($a_value !== null) {
          $key = $this->getMappedName($key);
          $return[$key] = $this->nullPlaceholderCheck($a_value);
        }
      }
      return $return;
    }
    return $value;
  }