// It panics if v's [Kind] is not [KindGroup].
func (v Value) Group() []Attr {
	if sp, ok := v.any.(groupptr); ok {
		return unsafe.Slice((*Attr)(sp), v.num)
	}
	panic("Group: bad kind")
}

func (v Value) group() []Attr {
	return unsafe.Slice((*Attr)(v.any.(groupptr)), v.num)
}

//////////////// Other

// Equal reports whether v and w represent the same Go value.

    }

    public static <K, V> Map<K, Collection<V>> groupBy(Iterable<? extends V> iterable, InternalTransformer<? extends K, V> grouper) {
        ImmutableListMultimap.Builder<K, V> builder = ImmutableListMultimap.builder();

        for (V element : iterable) {
            K key = grouper.transform(element);
            builder.put(key, element);
        }

        return builder.build().asMap();
    }