public static Task<LobbyOperationResponse> AdmitLobbyParticipantsAsync(this LobbyManager mgr,
     IEnumerable<ConversationParticipant> lobbyParticipants, LobbyAdmitOptions options)
 {
   return Task<LobbyOperationResponse>.Factory.FromAsync(mgr.BeginAdmitLobbyParticipants,
       mgr.EndAdmitLobbyParticipants, lobbyParticipants, options,
       null);
 }
 public static Task<LobbyOperationResponse> AdmitLobbyParticipantsAsync(this LobbyManager mgr,
     IEnumerable<ConversationParticipant> lobbyParticipants, LobbyAdmitOptions options)
 {
     return Task<LobbyOperationResponse>.Factory.FromAsync(mgr.BeginAdmitLobbyParticipants,
         mgr.EndAdmitLobbyParticipants, lobbyParticipants, options,
         null);
 }