CommandUnitOfWorkBehavior 中 CommitAsync 为何要执行两遍？

[yc-2503]

class CommandUnitOfWorkBehavior 中 第 54 行

            await using var transaction = _unitOfWork.BeginTransaction();
            {
                try
                {
                    WriteCommandBegin(new CommandBegin(id, commandName, request));
                    var response = await next();
                    WriteCommandEnd(new CommandEnd(id, commandName, request));
                    await _unitOfWork.SaveEntitiesAsync(cancellationToken);
                    await _unitOfWork.CommitAsync(cancellationToken); 
                    return response;
                }
                catch (Exception e)
                {
                    WriteCommandError(new CommandError(id, commandName, request, e));
                    await _unitOfWork.RollbackAsync(cancellationToken);
                    throw;
                }
            }

_unitOfWork.SaveEntitiesAsync 中已经执行了CommitAsync ,为何这里还要再执行一遍

[witskeeper]

_unitOfWork.SaveEntitiesAsync仅当未开启事物时，才会内部开启事物并在执行结束后提交事物。 在外部开启的事物，它是不会提交事物的，因此需要在外部提交事物。