I hesitate to defend Apple developer documentation. I have struggled with it for 30 some years, but if you don't understand OOP on the mac (inheritance etc.),

I hesitate to defend Apple developer documentation. I have struggled with it for 30 some years, but if you don't understand OOP on the mac (inheritance etc.), you probably shouldn't attempt to program the mac. This reminds me of a UNIX programmer I worked with who called up our Apple sales rep and berated her and Apple because programming macOS wasn't like programing UNIX. When I called her to apologize, she was nearly in tears. You are way outside this field. Programming the macOS can be very different and difficult. Either learn its concepts or work on something else.