Updated InProceedingsImExporter to implement new interface

sci-publications/src/main/java/org/scientificcms/publications/InProceedingsImExporter.java

@@ -22,9 +22,28 @@ public class InProceedingsImExporter
     }
 
     @Override
-    @PostConstruct
-    protected void init() {
+    protected void initPublicationImExporter() {
         addRequiredEntities(Set.of(Proceedings.class));
     }
 
+    @Override
+    protected void updateExistingPublication(
+        final InProceedings existingPublication,
+        final InProceedings withImportedPublication
+    ) {
+        if (existingPublication.getStartPage() != withImportedPublication
+            .getStartPage()) {
+            existingPublication.setStartPage(
+                withImportedPublication.getStartPage()
+            );
+        }
+
+        if (existingPublication.getEndPage() != withImportedPublication
+            .getEndPage()) {
+            existingPublication.setEndPage(
+                withImportedPublication.getEndPage()
+            );
+        }
+    }
+
 }