The header file is quite simple:
@interface HelloWorld : CCLayer
// returns a Scene that contains the HelloWorld as the only child
The private methods are however declared in the .m file as shown below with "(PrivateMethods)" added behind "@interface":
// private methods are declared in this manner to avoid "may not respond to ..." compiler warnings
@interface HelloWorld (PrivateMethods)
-(void) onCallFuncND:(id)sender data:(void*)data;
This is completely new to me and indeed quite interesting!