public void TestUserRegistrationIfUserAlreadyPresent()
{
User user = new User("ShilpaG", "test123", "[email protected]");
var mock = new Mock<IRepository>();
mock.Setup(ps => ps.IsUserPresent(user.Username)).Returns(true).AtMostOnce();
Assert.IsFalse(user.Register(mock.Object));
mock.VerifyAll();
}