mapper/types.go
func MostSpecificType(types []string) (string, error) {
	if len(types) == 0 {
		return "", errors.New("no types supplied")
	}
	sorted, err := SortTypes(types)
	if err != nil {
		return "", err
	}
	return sorted[len(sorted)-1], nil
}
func MostSpecificType(types []string) (string, error) {
	if len(types) == 0 {
		return "", errors.New("no types supplied")
	}
	sorted, err := SortTypes(types)
	if err != nil {
		return "", err
	}
	return sorted[len(sorted)-1], nil
}
// MostSpecific returns the most specific from a list of types in an hierarchy
// behaviour is undefined if any of the types are siblings.