let server port =
  let inet_addr = inet_addr_any in
  let sockaddr = ADDR_INET (inet_addr, port) in
  let domain = domain_of_sockaddr sockaddr in
  Lwt_main.run (
  let%lwt _=Lwt_io.printf "started run\n" in
  let sock = Lwt_unix.socket domain SOCK_STREAM 0 in
  let%lwt _=Lwt_io.printf "sock created\n" in
  Lwt_unix.bind sock sockaddr;
  let%lwt _=Lwt_io.printf "bind done\n"  in
  Lwt_unix.listen sock 10;
  let%lwt _=Lwt_io.printf "listen done, will Lwt.return call to accept_connection\n" in
  accept_connection sock)