public async Task CantCreateWithWrongRolesSetUser()
        {
            var userDto = new UserDto
            {
                Email    = "*****@*****.**",
                Login    = "******",
                Name     = "Lalalal",
                Password = "******",
                RolesIds = new List <int> {
                    666, 777, 888
                }                                       // wrong role's set
            };

            var userService = new UserService(_mockUserRepository.Object, _mockRoleRepository.Object);

            try
            {
                var res = await userService.Create(userDto);
            }
            catch (EntityNotExistsException e)
            {
                // Just pass, it's not important here
            }

            _mockUserRepository.Verify(x =>
                                       x.SaveAsync(It.IsAny <User>()), Times.Never);
        }
        public async Task CanCreateWithoutRolesUser()
        {
            var userDto = new UserDto
            {
                Email    = "*****@*****.**",
                Login    = "******",
                Name     = "Lalalal",
                Password = "******",
                RolesIds = new List <int>() // without roles
            };

            var userService = new UserService(_mockUserRepository.Object, _mockRoleRepository.Object);

            var res = await userService.Create(userDto);

            _mockUserRepository.Verify(x
                                       => x.SaveAsync(It.IsAny <User>()), Times.Once);
        }