如何返回DocumentSnapSpot作为方法的结果?
public UserSettings getUserSettings(DocumentSnapshot documentSnapshot){ Log.d(TAG, "getUserSettings: retrieving user account settings from firestore"); DocumentReference mSettings = mFirebaseFirestore.collection("user_account_settings").document(userID); mSettings.get().addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() { @Override public void onSuccess(DocumentSnapshot documentSnapshot) { UserAccountSettings settings = documentSnapshot.toObject(UserAccountSettings.class); settings.setDisplay_name(documentSnapshot.getString("display_name")); settings.setUsername(documentSnapshot.getString("username")); settings.setWebsite(documentSnapshot.getString("website")); settings.setProfile_photo(documentSnapshot.getString("profile_photo")); settings.setPosts(documentSnapshot.getLong("posts")); settings.setFollowers(documentSnapshot.getLong("followers")); settings.setFollowing(documentSnapshot.getLong("following")); } });}