For example, suppose you want to implement the tune operation. In the window, select tune, then click OK.

The PllTuner class implements the tune operation and displays it in the browser. If you select Implement Base Classes for the PllTuner class again, the tune operation is no longer listed as a required or optional element. Click Implemented to see that the tune operation was implemented and is now displayed in gray, as shown in this example.

If an element has been implemented (it displays in gray in the tree and is checked), you cannot clear ("unrealize") it.