public AuthRequest(string assertionConsumerServiceUrl, string issuer, string audienceRestriction, string requestedAuthnContextComparisonMethod, List<string> authnContextClassRefs)
{
_assertionConsumerServiceUrl = assertionConsumerServiceUrl;
_issuer = issuer;
_audienceRestriction = audienceRestriction;
Id = "_" + Guid.NewGuid();
_issueInstant = DateTime.Now.ToUniversalTime().ToString("yyyy-MM-ddTHH:mm:ssZ");
_requestedAuthnContextComparisonMethod = string.IsNullOrWhiteSpace(requestedAuthnContextComparisonMethod)
? "minimum"
: requestedAuthnContextComparisonMethod;
if (authnContextClassRefs == null || !authnContextClassRefs.Any())
authnContextClassRefs = DefaultAuthnContextClassRefs();
_authnContextClassRefs = authnContextClassRefs;
}