         }
         return nil
     }
-}+}

    // MARK: Properties
    
    private var observers: [(observer: WeakWrapper, callbacks: [CallBackType])] = []
    
    // MARK: Initializers
    
    public init() {}
    
    // MARK: Methods
    
    /**

        else {
            // since the observer does not already exist, add a new tuple with the
            // observer and an array with the callback
            let oldCount = self.observers.count
            self.observers.append((observer: WeakWrapper(observer), callbacks: [callback]))
            if oldCount == 0 {
                self.onHasObserverChanged?(true)
            }
        }
    }
    
