private void annotateExtension(Extension extension, DomElementAnnotationHolder holder) {
          final ExtensionPoint extensionPoint = extension.getExtensionPoint();
          if (extensionPoint == null) {
            return;
          }
          final GenericAttributeValue<PsiClass> interfaceAttribute = extensionPoint.getInterface();
          if (!DomUtil.hasXml(interfaceAttribute)) {
            return;
          }

          final PsiClass value = interfaceAttribute.getValue();
          if (value != null && value.isDeprecated()) {
            final Annotation annotation =
                holder.createAnnotation(extension, HighlightSeverity.WARNING, "Deprecated EP");
            annotation.setHighlightType(ProblemHighlightType.LIKE_DEPRECATED);
          }
        }