How can we check if provided culture is supported?

[mastef]

Currently it seems that if we provide an unsupported culture to someDate.Humanize(culture: someCulture), we may get back the UI culture - which could be english instead of e.g. hindi. How can we instead check if Humanize supports the provided culture, so we could fallback to another solution - like showing the date in the unsupported culture.

LocaliserRegistry.FindLocaliser seems to be private, and also returns _defaultLocaliser if not found.
LocalizerRegistry.ResolveForCulture falls back to CultureInfo.CurrentUICulture.

Maybe a bool isSupported(culture) method would be nice.