java - How to add subcollection to a document in Firebase Cloud Firestore

Question

The documentation does not have any examples on how to add a subcollection to a document. I know how to add document to a collection and how to add data to a document, but how do I add a collection (subcollection) to a document?

Shouldn't there be some method like this:

dbRef.document("example").addCollection("subCollection")

Answer 1

Waitting for answers