public override ACCredentialHolder GetCredentialHolder(string credentialHolderId)
 {
     // This is called when credential holder isn't already cached - look up synchronously
     try
     {
         var credentialHolderDecriptor = _client.GetCredentialHolder(credentialHolderId);
         if (credentialHolderDecriptor != null)
         {
             return(TypeConverter.ToACCredentialHolder(credentialHolderDecriptor, _systemProperties));
         }
     }
     catch (DemoApplicationClientException ex)
     {
         ACUtil.Log(true, "DemoACPlugin.CredentialHolderManager", "Error looking up credential holder: " + ex.Message);
     }
     return(null);
 }