@Override
    public Socket createSocket() throws IOException {
        return configure(delegate.createSocket());
    }
@Test
    void keepAliveFlagIsSet() throws IOException {
        final TcpKeepAliveSocketFactory factory = new TcpKeepAliveSocketFactory(SocketFactory.getDefault());
        final Socket socket = factory.createSocket();
        Assertions.assertThat(socket.getKeepAlive()).isTrue();
        socket.close();
    }