code: public void createGroup(String groupId, String unitId, TransactionInfo transactionInfo, String transactionType)
              throws TransactionException {
          //创建事务组
          try {
              // 日志
              txLogger.txTrace(groupId, unitId,
                      "create group > transaction type: {}", transactionType);
              // 创建事务组消息
              reliableMessenger.createGroup(groupId);
              // 缓存发起方切面信息
              aspectLogger.trace(groupId, unitId, transactionInfo);
          } catch (RpcException e) {
              // 通讯异常
              dtxExceptionHandler.handleCreateGroupMessageException(groupId, e);
          } catch (LcnBusinessException e) {
              // 创建事务组业务失败
              dtxExceptionHandler.handleCreateGroupBusinessException(groupId, e.getCause());
          }
          txLogger.txTrace(groupId, unitId, "create group over");
      }
docs: Client创建事务组操作集合
  
  @param groupId         groupId
  @param unitId          unitId
  @param transactionInfo txTrace
  @param transactionType transactionType
  @throws TransactionException 创建group失败时抛出