The response for Firestore.Listen.

Attributes

• documentChange (DocumentChange): A Document has changed. Defaults to: null.
• documentDelete (DocumentDelete): A Document has been deleted. Defaults to: null.
• documentRemove (DocumentRemove): A Document has been removed from a target (because it is no longer relevant to that target). Defaults to: null.
• filter (ExistenceFilter): A filter to apply to the set of documents previously returned for the given target. Returned when documents may have been removed from the given target, but the exact documents are unknown. Defaults to: null.
• targetChange (TargetChange): Targets have changed. Defaults to: null.