public void Copy(HttpDigestClientElement from) { if (this.IsReadOnly()) { throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ConfigurationErrorsException(System.ServiceModel.SR.GetString("ConfigReadOnly"))); } if (from == null) { throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("from"); } this.ImpersonationLevel = from.ImpersonationLevel; }