Result+Response.swift

public extension Result where Success == (data: Data, response: URLResponse) {
    func map<T>(_ keyPath: KeyPath<Success, T>) -> Result<T, Failure> {
        switch self {
        case .success(let response):
            return .success(response[keyPath: keyPath])
        case .failure(let error):
            return .failure(error)
        }
    }
}