flatmapLatest_combine

extension Publisher {

//    The flatMapLatest operator behaves much like the standard FlatMap operator, except that whenever
//    a new item is emitted by the source Publisher, it will unsubscribe to and stop mirroring the Publisher
//    that was generated from the previously-emitted item, and begin only mirroring the current one.
    func flatMapLatest<T: Publisher>(_ transform: @escaping (Self.Output) -> T) -> Publishers.SwitchToLatest<T, Publishers.Map<Self, T>> where T.Failure == Self.Failure {
        map(transform).switchToLatest()
    }
}