func (w *SnowballWord) FirstSuffix(suffixes ...string) (suffix string, suffixRunes []rune) {
	return w.FirstSuffixIfIn(0, len(w.RS), suffixes...)
}
func (w *SnowballWord) FirstSuffix(suffixes ...string) (suffix string, suffixRunes []rune) {
	return w.FirstSuffixIfIn(0, len(w.RS), suffixes...)
}
// Return the first suffix found or the empty string.