Обсуждение: Role members

Hello! I have the following question.

For example I have a role ID1 with members ID2 and ID3.
Role ID2 has also members ID4 and ID5. It means that roles ID4 and ID5 are members of ID1.
The question: Is there any function in PostgreSQL, that finds all the members of role ID1 - even such members, as ID4 and ID5.

Thanks.