问在防火墙响应之前执行的返回语句

EN

public List<Users> getAllUsers() {
    return loadAllUserData();
}
private List<Users> loadAllUserData() {
    List<Users> usersList  = new ArrayList<>();

    mFirebaseFirestore.collection(USER_DATA).get()
            .addOnSuccessListener(queryDocumentSnapshots -> {
                List<DocumentSnapshot> docSnap = 
                queryDocumentSnapshots.getDocuments();
                
                for (DocumentSnapshot docs : docSnap) {
                    Users user = docs.toObject(Users.class);
                    usersList.add(user);
                    Log.d(TAG, "onSuccess: loaded Users : " + usersList.size());
                }
            });
    Log.d(TAG, "loadAllUserData: Returning users : " + usersList.size());

    return usersList;
}