Removed some more final modifiers

ccm-cms/src/main/java/org/librecms/assets/AbstractAssetImExporter.java

@@ -46,9 +46,19 @@ public abstract class AbstractAssetImExporter<T extends Asset>
     @Any
     private ItemAttachmentImExporter itemAttachmentImExporter;
 
+    /**
+     * Implementation of {@link AbstractEntityImExporter#init()} for
+     * {@link Asset}s.
+     *
+     * !!! Warning: Implementations of this abstract class MUST NEVER override
+     * this method. Instead, they MUST implement {@link #initAssetImExporter()}.
+     *
+     * Unfortunetly, CDI does not support final methods, therefore we can't make
+     * this method final.
+     */
     @PostConstruct
     @Override
-    protected final void init() {
+    protected void init() {
         // ItemAttachmentImExporter requires that all assets to be imported
         itemAttachmentImExporter.addRequiredEntities(Set.of(getEntityClass()));
 

ccm-cms/src/main/java/org/librecms/contentsection/AbstractContentItemImExporter.java

@@ -65,9 +65,20 @@ public abstract class AbstractContentItemImExporter<T extends ContentItem>
     @Processes(RelatedLink.class)
     private RelatedLinkImExporter relatedLinkImExporter;
 
+    /**
+     * Implementation of {@link AbstractEntityImExporter#init()} for
+     * {@link ContentItems}s.
+     *
+     * !!! Warning: Implementations of this abstract class MUST NEVER override
+     * this method. Instead, they MUST implement {@link #initContentItemImExporter()
+     * }.
+     *
+     * Unfortunetly, CDI does not support final methods, therefore we can't make
+     * this method final.
+     */
     @PostConstruct
     @Override
-    protected final void init() {
+    protected void init() {
         addRequiredEntities(
             Set.of(
                 Category.class,