public interface DataObject extends Serializable
Inherently immutable objects may optionally return the same object without modification from clone(), rather than constructing a new instance.
Note that a read-only object is not necessarily immutable; if reference types are returned from accessors, then callers could theoretically mutate those objects even if the top-level object is marked as read-only. The ability to make objects read-only is intended to catch programming errors (e.g. attempting to modify a data object passed as part of a SLEE event), not to provide an absolute guarantee of immutability.
Calling setReadOnly() on an object that is already read-only is a no-op.
Some DataObject implementations may be inherently immutable. In those cases, they are considered always read-only.