func (s StringSlice) ExistsAllIgnoreCase(str []string) bool {
	for _, v := range str {
		if !s.ExistsIgnoreCase(v) {
			return false
		}
	}

	return true
}
func (s StringSlice) ExistsAllIgnoreCase(str []string) bool {
	for _, v := range str {
		if !s.ExistsIgnoreCase(v) {
			return false
		}
	}

	return true
}
func ( s StringSlice ) ExistsAllIgnoreCase ( str [ ] string ) bool { for _ , v := range str { if ! s . ExistsIgnoreCase ( v ) { return false } } return true }
//ExistsAllIgnoreCase determine whether all specified strings exists into
// current slice (ignores letter casing).
ExistsAllIgnoreCase determine whether all specified strings exists into current slice ( ignores letter casing ) .