public void UserManagementLogic_UserExists_RepositoryReturnsNull_ReturnsFalse()
{
Mock <IConfigurationRepository> configurationRepository = new Mock <IConfigurationRepository>();
configurationRepository.Setup(x => x.Get <AuthenticablePrincipal>(It.IsAny <Guid>())).Returns((AuthenticablePrincipal)null);
UserManagementLogic userManagementLogic = new UserManagementLogic(configurationRepository.Object, new AuthorizeInitialSetup(configurationRepository.Object));
bool result = userManagementLogic.UserExists(Guid.NewGuid());
Assert.IsFalse(result);
}