You can use Class Builder to choose a superclass for your class and override the superclass methods.
To choose the superclass
Start Class Builder and make sure your class is selected by Class Builder. For information on how to do this, see Starting Class Builder.
Click the Extends tab in Class Builder.
The Superclass Name box displays the current superclass. To specify a different superclass, click Select Superclass.
In the Select Superclass dialog box, select a superclass from the drop-down list. If the class you want to derive from is not listed, enter the name of the class in the edit box portion of the list. Note, however, that this class is not added to the list for subsequent use.
Click OK.
To override a superclass method
On the Extends tab in Class Builder, select a method from the Inherited Methods list. This list displays all methods inherited from the superclass.
Click the right arrow button to move the method to the Local Overrides list. A declaration for the method is then inserted into your class, where you can add your implementation. (Note that if you select a superclass method that cannot be overridden, the right arrow button is disabled.)
The Local Overrides list displays all superclass methods that your class has overridden. To remove an overridden method, select the method from the Local Overrides list and click the left arrow button. Any associated code is removed from your source file.