/// <summary>
/// Checks if an enrollee with the given email and pin is in the
/// database and that the pin is correct.
/// </summary>
/// <param name="email"></param>
/// <param name="pin"></param>
/// <returns></returns>
public Enrollee LoginEnrollee(string email, string pin)
{
Enrollee enrollee = Mgr.GetEnrolleeByEmail(email);
// since enrollee can be null we need to check if it is equal to true
return(((enrollee.Email.Equals("guest@guest") &&
email.Equals("guest@guest") &&
pin == enrollee.Pin) ||
enrollee?.Login(email, pin) == true) ? enrollee: null);
}