public InviteAVolunteerTests()
        {
            _fakeClock = Substitute.For <ISystemClock>();
            _fakeInvitationRepository = new FakeInvitationRepository();
            _fakeVolunteerRepository  = new FakeVolunteerRepository();
            _mediator = Substitute.For <IMediator>();

            _handler = new InviteAVolunteerHandler(new InvitationCodesGenerator(), _mediator, _fakeClock, _fakeInvitationRepository, _fakeVolunteerRepository);
        }
        public RegisterVolunteerTests()
        {
            _fakeClock = Substitute.For <ISystemClock>();
            var jwtGenerator = Substitute.For <IJwtGenerator>();

            jwtGenerator.Generate(Arg.Any <User>()).Returns("something");
            _fakeInvitationRepository = new FakeInvitationRepository();
            _fakeVolunteerRepository  = new FakeVolunteerRepository();
            _passwordHasher           = Substitute.For <IPasswordHasher <User> >();
            _handler = new RegisterVolunteerHandler(jwtGenerator, _fakeClock, _fakeInvitationRepository, _fakeVolunteerRepository, _passwordHasher);
        }