code: func (s *Server) Stop() {
  	close(s.chDone)
  	Logger.Print("gracefully closing client connections...")
  	s.wg.Wait()
  	Logger.Print("all clients connection closed")
  }
docs: // Termination of the LDAP session is initiated by the server sending a
  // Notice of Disconnection.  In this case, each
  // protocol peer gracefully terminates the LDAP session by ceasing
  // exchanges at the LDAP message layer, tearing down any SASL layer,
  // tearing down any TLS layer, and closing the transport connection.
  // A protocol peer may determine that the continuation of any
  // communication would be pernicious, and in this case, it may abruptly
  // terminate the session by ceasing communication and closing the
  // transport connection.
  // In either case, when the LDAP session is terminated.