public interface Saveable
This interface is a "marker" used to indicate to the VisAD
binary file code that an object should be saved in binary
format.
Any class which extends one of the base VisAD Data classes can
implement Saveable to indicate that it should be saved as if
it were the parent Data class.
If a class which extends a base Data class does not implement
Saveable, it will be saved as a serialized object.