public async Task <IEnumerable <ChatMessageDTO> > GetAllMessagesByGroupId(Guid groupId) { _logger.Info(String.Format($"{"ChatService",-20} >>> {"GetAllMessagesByGroupId",-20} >>> {"Start",-10} >>> {"GroupId",-10}{groupId}")); IEnumerable <ChatMessageDTO> result = null; if (groupId == null || groupId == Guid.Empty) { return(result); } result = await _chatRepository.GetAllMessagesByGroupId(groupId); _logger.Debug($"{"ChatService:",-20} >>> {"GetAllMessagesByGroupId",-20} >>> {"Result:",-10} {JsonConvert.SerializeObject(result)}, {"GroupId:",-10}{groupId}."); return(result); }