fileprivate struct PostmanEchoTimeStampCheckResponse: Codable {
    let valid: Bool
}

let dataProvider = PassthroughSubject<PostmanEchoTimeStampCheckResponse, Never>()
    .encode(encoder: JSONEncoder())
    .sink { data in
        print(".sink() data received \(data)")
        let stringRepresentation = String(data: data, encoding: .utf8)
        print(stringRepresentation)
    })

let testUrlString = "https://postman-echo.com/time/valid?timestamp=2016-10-10"
// checks the validity of a timestamp - this one should return {"valid":true}
// matching the data structure returned from https://postman-echo.com/time/valid
fileprivate struct PostmanEchoTimeStampCheckResponse: Decodable, Hashable {
    let valid: Bool
}

let remoteDataPublisher = URLSession.shared.dataTaskPublisher(for: URL(string: testUrlString)!)
    // the dataTaskPublisher output combination is (data: Data, response: URLResponse)
    .map { $0.data }
    .decode(type: PostmanEchoTimeStampCheckResponse.self, decoder: JSONDecoder())