public void WhenAddingSameExternalLoginTwiceItIgnoresSecond()
{
// Arrange
User u = new User("Bent", null, null, UserNameValidator, EmptyPasswordPolicy);
// Act
u.AddExternalLogin("Google", "xyz");
u.AddExternalLogin("Google", "abc");
u.AddExternalLogin("Google", "xyz");
// Assert
Assert.IsTrue(u.HasExternalLogin("Google", "xyz"));
Assert.IsTrue(u.HasExternalLogin("Google", "abc"));
Assert.AreEqual(2, u.GetExternalLogins().Count());
}