enum deserialization of missing values to null

My domain class has one field as an enum.

Recently I decided to change the enum values for a better readeability. But know when trying to load users from firebase i get the exception.

`Giveaway giv = ds.getValue(Giveaway.class);`

```
Process: com.tomatedigital.instagramgiveawaywinner, PID: 21593
com.google.firebase.database.DatabaseException: Could not find enum value of com.tomatedigital.giveawaymaster.domain.CommentListType for value "COMMON_NAMES"
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToEnum(com.google.firebase:firebase-database@@19.2.1:314)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.1:229)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToType(com.google.firebase:firebase-database@@19.2.1:178)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.access$100(com.google.firebase:firebase-database@@19.2.1:47)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.1:592)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.1:562)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(com.google.firebase:firebase-database@@19.2.1:432)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.1:231)
at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(com.google.firebase:firebase-database@@19.2.1:79)
at com.google.firebase.database.DataSnapshot.getValue(com.google.firebase:firebase-database@@19.2.1:203)
at com.tomatedigital.giveawaymaster.firabase.LoginValueEventListener$3.onDataChange(LoginValueEventListener.java:178)
at com.google.firebase.database.Query$1.onDataChange(com.google.firebase:firebase-database@@19.2.1:179)
at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@19.2.1:75)
at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@19.2.1:63)
at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@19.2.1:55)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
```

`COMMON_NAMES` was changed to something else.

I completely understand the reason of this exception... my question is "are there any workaround?"...

I wish i could tell firebase to map unexisting enum values to `null` or any value, so then i could manually deal with them...

Is a very complicated restriction to throw a fatal exception like this on deserialization for a missing value... it means that ALL APPS RUNNING FIREBASE WONT BE ALLOWED TO REMOVE ENUM VALUES FOREVER...