private void DeleteUserHistoryAsync(TLChannel channel, TLInputUserBase userId, Action <TLAffectedHistory> callback, Action <TLRPCError> faultCallback = null) { MTProtoService.DeleteUserHistoryAsync(channel, userId, result => { if (result.Offset.Value > 0) { DeleteUserHistoryAsync(channel, userId, callback, faultCallback); } else { callback.SafeInvoke(result); } }, error => { Telegram.Api.Helpers.Execute.ShowDebugMessage("channels.deleteUserHistory error " + error); }); }