protected function isGovCMSTheme(array $package) {
    // Exlucde package theme from custom repos.
    if ($package['name'] == 'govcms-custom/govcms8_uikit' || $package['name'] == 'govcms-custom/govcms8_uikit_starter') {
      return FALSE;
    }

    $package_types = [
      'drupal-theme',
    ];
    return (
      in_array($package['type'], $package_types) &&
      array_key_exists($package['name'], $this->rootPackage->getRequires())
    );
  }