java - How to check if the field exists in firestore?

Question

I am checking whether the Boolean field called attending exists, however I am not sure how to do that.

Is there a function such as .child().exists() or something similar that I could use?

firebaseFirestore.collection("Events")
    .document(ID)
    .collection("Users")
    .get()
    .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
        @Override
        public void onComplete(@NonNull Task<QuerySnapshot> task) {
            if(task.isSuccessful()) {
                for(QueryDocumentSnapshot document: task.getResult()){
                    attending = document.getBoolean("attending");
                }
            }
        }
    });

Answer 1

Waitting for answers