Use one selector to provide many methods with similar implementations.

FZAUIElement.m

#import <Foundation/Foundation.h>
#import <objc/runtime.h>

@interface FZAUIElement : NSObject

- (id)initWithAXUIElement: (AXUIElementRef)anElement;
- (BOOL)press: (NSError *__autoreleasing*)error;
- (BOOL)cancel: (NSError *__autoreleasing*)error;

@end

extern NSString const *FZAUIElementErrorDomain;

@interface FZAUIElement ()

BOOL doTheThing(id self, SEL _cmd, NSError * __autoreleasing *error);
+ (CFStringRef)actionForSelector: (SEL)selector;
+ (BOOL)hasActionForSelector: (SEL)selector;
- (AXUIElementRef)element;

@end

static NSDictionary *actionSelectorMap;

@implementation FZAUIElement
{
    AXUIElementRef element;
}

+ (void)initialize {
    actionSelectorMap = [NSDictionary dictionaryWithObjectsAndKeys:
                         (__bridge id)kAXPressAction, 
                         @"press:",
                         (__bridge id)kAXCancelAction,
                         @"cancel:",
                         nil];
}

- (id)initWithAXUIElement:(AXUIElementRef)anElement {
    self = [super init];
    if (self) {
        CFRetain(anElement);
        element = anElement;
    }
    return self;
}

- (void)dealloc {
    if (element) {
        CFRelease(element);
    }
}

+ (BOOL)resolveInstanceMethod:(SEL)sel {
    if ([self hasActionForSelector: sel]) {
        class_addMethod(self, sel, (IMP)doTheThing, "c@:@");
        return YES;
    }
    else {
        return [super resolveInstanceMethod: sel];
    }
}

BOOL doTheThing(id self, SEL _cmd, NSError *__autoreleasing *error) {
    CFStringRef action = [[self class] actionForSelector: _cmd];
    AXError returnCode = AXUIElementPerformAction([self element], action);
    if (returnCode == kAXErrorSuccess) {
        return YES;
    } else {
        if (error) {
            *error = [NSError errorWithDomain: (NSString *)FZAUIElementErrorDomain code: returnCode userInfo: nil];
        }
        return NO;
    }
}

+ (CFStringRef)actionForSelector:(SEL)selector {
    NSString *selectorName = NSStringFromSelector(selector);
    return (__bridge CFStringRef)[actionSelectorMap objectForKey: selectorName];
}

+ (BOOL)hasActionForSelector:(SEL)selector {
    return ([actionSelectorMap objectForKey: NSStringFromSelector(selector)] != nil);
}

- (AXUIElementRef)element {
    return element;
}
@end

NSString const *FZAUIElementErrorDomain = @"FZAUIElementErrorDomain";