myObject.m - With convenience initializer

myObject.m

@interface MyObject()
@property (nonatomic) BOOL isNightMode 
@property (strong, nonatomic) MyOtherObject *theObjectDoingSomethingElse
@end

@implementation MyObject

#pragma mark - Initializers
//2
- (instancetype)initWithTheOtherObjectDoingSomethingElse:(MyOtherObject *)alreadyExisitingObject isNightModeOn:(BOOL)isNightMode {
	self= [super init];
	if (self) {
		_isNightMode = isNightMode;
		_theObjectDoingSomethingElse = alreadyExisitingObject;
	}
}

- (instancetype)initWithTheOtherObjectDoingSomethingElse:(MyOtherObject *)alreadyExisitingObject {
	return [self initWithTheOtherObjectDoingSomethingElse:alreadyExisitingObject isNightModeOn:NO];
}
@end