code: function resolveLocale(locales) {
  	const localesFingerprint = locales.toString()
  	if (resolvedLocales[localesFingerprint]) {
  		return resolvedLocales[localesFingerprint] 
  	}
  	return resolvedLocales[localesFingerprint] = intlDateTimeFormatSupportedLocale(locales)
  }
docs: Resolves a list of possible locales to a single ("best fit") supported locale.
  @param  {string[]} locales
  @return {string}