如何在objective c init中将对象作为依赖项传递?

这是我的objc接口:

@interface MobileKeysController : NSObject <MobileKeysManagerDelegate>
- (id) initWithLogger:(Loggable *)logger; //issue: Expected a type
- (void) didPressRegistrationButton:(NSString *)code;
@end

我还有一个私人界面:

@interface MobileKeysController ()
@property(nonatomic) Loggable *logger;
@end

和自定义初始化:

- (id)initWithLogger: (Loggable *) logger_ {
    self = [super init];
    // how can I assign it here from an init?
    return self;
}

这是我的Swift定义:

protocol Loggable: class {
    func log(_ category: FirebaseCategory, _ type: FirebaseEventType, _ dataProvider: FirebaseEventDataProvider)
}

@objc class FirebaseLogger: NSObject, Loggable {
    // MARK: - Loggable
    func log(_ category: FirebaseCategory, _ type: FirebaseEventType, _ dataProvider: FirebaseEventDataProvider) {
        log(category.rawValue, type.value, dataProvider.parameters)
    }
}

我需要像这样使用Swift文件:

let logger = FirebaseLogger()
return MobileKeysController(logger: logger)