#### 7.2.3 Customizing the Change of Class of an Instance

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 Shared-Initialize.