finalize Value
Disallows further changes to the value of this property. Calls to methods that change the value of this property, such as set or put will fail.
When this property has elements provided by a Provider, the value of the provider is queried when this method is called and the value of the provider will no longer be tracked.
Note that although the value of the property will not change, the resulting map may contain mutable objects. Calling this method does not guarantee that the value will become immutable.