public void find_all_known()
        {
            var issuers = new SamlCertificate[]
            {
                new SamlCertificate{Issuer = "foo:bar1"}, 
                new SamlCertificate{Issuer = "foo:bar2"}, 
                new SamlCertificate{Issuer = "foo:bar3"} 
            };

            var repository = new BasicSamlCertificateRepository(issuers);

            repository.AllKnownCertificates().ShouldHaveTheSameElementsAs(issuers);
        }