Couldn't implement Server::run_on_socket

[handewo]

   fn run_on_socket(
        &mut self,
        config: Arc<Config>,
        socket: &TcpListener,
    ) -> RunningServer<impl Future<Output = std::io::Result<()>> + Unpin + Send>

pub struct RunningServer<F: Future<Output = std::io::Result<()>> + Unpin + Send> {
    inner: F,
    shutdown_tx: broadcast::Sender<String>,
}

Because of all fields are private in RunningServer that is returned type of run_on_socket.