Cheat sheet for notification center (objc & swift)

NotificationsCheatSheet.swift

Post notification:
 * swift:
    NotificationCenter.default.post(name: .onCountryChanged, object: nil)
 * objc:
    [[NSNotificationCenter defaultCenter] postNotificationName:@"on-country-changed" object:nil];

Register notification:
 * swift:
     NotificationCenter.default.addObserver(self, selector: #selector(self.someSelector), name: .onCountryChanged, object: nil)
 * objc:
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(someSelector) name:@"on-country-changed" object:nil];

 Remove notification:
 * swift: 
    NotificationCenter.default.removeObserver(self, name: .onCountryChanged, object: nil)
 * objc:
    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"on-country-changed" object:nil];

Create Notification by name:
extension Notification.Name {
    static let onCountryChanged = Notification.Name("on-country-changed")
}