import Foundation

protocol NotificationCenter {
    func addObserver(_ observer: Any, selector aSelector: Selector, name aName: NSNotification.Name?, object anObject: Any?)
    func post(_ notification: Notification)
    func post(name aName: NSNotification.Name, object anObject: Any?)
    func post(name aName: NSNotification.Name, object anObject: Any?, userInfo aUserInfo: [AnyHashable: Any]?)
    func removeObserver(_ observer: Any)
    func removeObserver(_ observer: Any, name aName: NSNotification.Name?, object anObject: Any?)

    @discardableResult func addObserver(
        forName name: NSNotification.Name?,
        object obj: Any?,
        queue: OperationQueue?,
        using block: @escaping (Notification) -> Void
    ) -> NSObjectProtocol
}

extension Foundation.NotificationCenter: NotificationCenter {}