Setting Up the Game Environment: Creating Fixed Sprite Classes Using the Actor Superclass - Beginning Java 8 Games Development - page 436

Figure 14-3 . Use the Alt-Enter work process to pop up a helper dialog filled with suggestions regarding fixing the
error
Remove the throw new UnsupportedOperationException() and create an empty
.update() method for now.
Figure 14-4. NetBeans generates abstract method for you; remove the throw new statement; create an empty method