mutable
The sole FillerDescriptor, which is Mutability.MUTABLE. There are no immutable or shared filler descriptors, because if a filler is embedded in some other object structure which is being made immutable or shared, it's always an error.
The sole FillerDescriptor, which is Mutability.MUTABLE. There are no immutable or shared filler descriptors, because if a filler is embedded in some other object structure which is being made immutable or shared, it's always an error.