function warnUserAboutLanguageRegistration(languageCode) {
  if ((0, _mixed.isDefined)(languageCode)) {
    (0, _console.error)((0, _templateLiteralTag.toSingleLine)(_templateObject(), languageCode));
  }
}
Warn user if there is no registered language.

@param {String} languageCode Language code for specific language i.e. 'en-US', 'pt-BR', 'de-DE'.