public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
        {
            _log.Write(_id, SPTraceLogger.TraceSeverity.InformationEvent, "Feature1EventReceiver", "Info", "FeatureDeactivating");

            SPWebApplication rootApp = properties.Feature.Parent as SPWebApplication;
            SPExpressionBuilderConfigModifications express = new SPExpressionBuilderConfigModifications();
            express.RemoveConfigModifications(rootApp, _owner);
        }
 // We've already deactivated features, this is a last ditch to remove mods if feature deactivation hasn't covered them
 private void RemoveConfig(SPWebApplication webApp)
 {
     SPExpressionBuilderConfigModifications express = new SPExpressionBuilderConfigModifications();
     express.ForceRemoveConfigModifications(webApp, _owner);
 }