Updated GreyLiteratureImExporter to implement updated interface

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

@@ -5,7 +5,6 @@ import org.librecms.assets.Organization;
 
 import java.util.Set;
 
-import javax.annotation.PostConstruct;
 import javax.enterprise.context.RequestScoped;
 
 /**
@@ -23,9 +22,28 @@ public class GreyLiteratureImExporter
     }
 
     @Override
-    @PostConstruct
     protected void initUnPublishedImExporter() {
         addRequiredEntities(Set.of(Organization.class));
     }
 
+    @Override
+    protected void updateExistingUnPublished(
+        final GreyLiterature existingPublication,
+        final GreyLiterature withImportedPublication
+    ) {
+        if (existingPublication.getStartPage() != withImportedPublication
+            .getStartPage()) {
+            existingPublication.setStartPage(
+                withImportedPublication.getStartPage()
+            );
+        }
+        
+        if (existingPublication.getEndPage() != withImportedPublication
+            .getEndPage()) {
+            existingPublication.setEndPage(
+                withImportedPublication.getEndPage()
+            );
+        }
+    }
+
 }