Methods for update-instance-for-different-class may be defined
to specify actions to be taken when an instance is updated. If only
after methods for update-instance-for-different-class are
defined, they will be run after the system-supplied primary method for
initialization and will not interfere with the default behavior of
update-instance-for-different-class.
Methods
for shared-initialize may be defined to customize class
redefinition. For more information, see Section 7.1.5 (Shared-Initialize).