public async Task Should_TolerateNullInput()
{
PersistenceService.GetPersistedSiteCertificateAsync()
.Returns(Task.FromResult(ValidCert));
var output = await Sut.RenewCertificateIfNeeded(null);
output.Status.Should().Be(LoadedFromStore);
Assert.AreSame(ValidCert, output.Certificate);
}