How to mark designated initializers of super class "invalid" in Objective-C? -

from adapting modern objective-c document:

if class provides 1 or more designated initializers, must implement of designated initializers of superclass.

that means if have subclass of nsobject has own designated initializer,

- (instancetype)initwithimage:(uiimage*)image ns_designated_initalizer; 

then need provide implementation of nsobjects -init. should mark -init initializer "invalid", i.e., nobody should call use -initwithimage: instead? what's best practice here?

edit

i tried techniques described here.

however, when mark superclass -init method unavailable in interface, compiler still tells me need overwrite initializer of superclass.

when try other techniques, i.e., raising exception or calling -doesnotrecognizeselector: inside of -init, error stating need call 1 of designated initializers.