SimpleListProperty becomes unmodifiable when deserializing a null value.

[WildeTechSolutions]

When you have a SimpleListProperty such as

private final SimpleListProperty<Part> parts = new SimpleListProperty<>(this, "parts", FXCollections.observableArrayList());

there is a problem when deserializing a json object that has a null value:

{
    "parts": null,
...
}

You will later get a java.lang.UnsupportedOperationException exception when trying to add objects to the list. It would be nice if there was an option to simply create an empty list when accepting a null value, that way we wouldn't have to then do a null check on the list's getter.