void MonClient::get_version(string map, version_t *newest, version_t *oldest, Context *onfinish)
{
  version_req_d *req = new version_req_d(onfinish, newest, oldest);
  ldout(cct, 10) << "get_version " << map << " req " << req << dendl;
  std::lock_guard l(monc_lock);
  auto m = ceph::make_message<MMonGetVersion>();
  m->what = map;
  m->handle = ++version_req_id;
  version_requests[m->handle] = req;
  _send_mon_message(std::move(m));
}
void MonClient::get_version(string map, version_t *newest, version_t *oldest, Context *onfinish)
{
  version_req_d *req = new version_req_d(onfinish, newest, oldest);
  ldout(cct, 10) << "get_version " << map << " req " << req << dendl;
  std::lock_guard l(monc_lock);
  auto m = ceph::make_message<MMonGetVersion>();
  m->what = map;
  m->handle = ++version_req_id;
  version_requests[m->handle] = req;
  _send_mon_message(std::move(m));
}