public function checkIgnoreDiffKeys(array $diff) {
    $result = [];
    $rules = $this->getRules();

    foreach ($diff as $config_key) {
      $ignore_key = FALSE;
      foreach ($rules as $rule) {
        if ($this->applyRule($config_key, $rule)) {
          // If any of rules are suitable - ignore changes for this config key.
          $ignore_key = TRUE;
        }
      }
      $result[$config_key] = $ignore_key;
    }

    // If at least one of the keys has FALSE - return FALSE.
    // This mean that we have changes, that can't be ignored.
    return !in_array(FALSE, $result);
  }