It isn't. I just had a look at the API. EDIT: It might be so that you don't override it in your world subclass and mess it up.

@kiarocks, in the summary of methods, it does not show as such; but, in the method descriptions, it does show 'public final void setBackground(...)' for both. I could be wrong, but, I doubt that the word 'final' should be there at all. What are you finalizing? 'void'?

No, if you look at the java specification for final, it it used in a method to prevent overrides of that particular method. (see this )

@kiarocks, I tried looking for something like that within the Java site, but was unable to locate it there. I was not aware of this functionality of 'final'. Thanks for the info.

I think, strictly speaking, they should both be final. The reason is that they are not intended to be overridden. They are called internally by Greenfoot and if they did not behave properly then they could cause Greenfoot itself to malfunction.