public static void AddOrUpdateCachedCertificate(string host, ACMECertificate certificate)
 {
     lock (_locker)
     {
         Instance.CachedCerts[host] = certificate;
     }
 }
        public static bool TryGetCachedCertificate(List <string> hosts, out ACMECertificate value)
        {
            if (Instance.CachedCerts.TryGetValue(hosts[0], out value) == false)
            {
                return(false);
            }

            if ((value.Certificate.NotAfter - DateTime.UtcNow).TotalDays < 14)
            {
                return(false);
            }

            return(true);
        }