func (s *HashSet[T]) Union(ss *HashSet[T]) *HashSet[T] {
	new := s.Copy()
	new.Merge(ss)
	return new
}
// Union makes a set that has all of the elements in either of two sets
Union makes a set that has all of the elements in either of two sets
// Union makes a set that has all of the elements in either of two sets
func (s *HashSet[T]) Union(ss *HashSet[T]) *HashSet[T] {
	new := s.Copy()
	new.Merge(ss)
	return new
}
func ( s * HashSet [ T ] ) Union ( ss * HashSet [ T ] ) * HashSet [ T ] { new := s . Copy ( ) new . Merge ( ss ) return new }
Union makes a set that has all of the elements in either of two sets
Union makes a set that has all of the elements in either of two sets