public async Task <RegisteredUserVm> Handle(RegisterUserCommand request, CancellationToken cancellationToken)
        {
            var userId = await _guidGenerator.GetNextAsync();

            var user = new User()
            {
                Id       = userId,
                Username = request.Username,
                Password = request.Password,
                About    = request.About
            };

            await _dbContext.Users.AddAsync(user, cancellationToken);

            await _dbContext.SaveChangesAsync(cancellationToken);

            return(new RegisteredUserVm()
            {
                Id = user.Id,
                Username = user.Username,
                About = user.About
            });
        }