public void CreateClientSecretIdentityAsync_WhenUserIdentityIsNull_ThrowsArgumentNullException()
{
ISecurityRepository sut = CreateSut();
ArgumentNullException result = Assert.ThrowsAsync <ArgumentNullException>(async() => await sut.CreateClientSecretIdentityAsync(null));
Assert.That(result.ParamName, Is.EqualTo("clientSecretIdentity"));
}