diff --git a/core/api/src/main/java/org/onosproject/ui/UiExtensionService.java b/core/api/src/main/java/org/onosproject/ui/UiExtensionService.java
index 9e03a51..f1ea508 100644
--- a/core/api/src/main/java/org/onosproject/ui/UiExtensionService.java
+++ b/core/api/src/main/java/org/onosproject/ui/UiExtensionService.java
@@ -56,6 +56,22 @@
     }
 
     /**
+     * Registers the specified topo hilighter factory.
+     *
+     * @param factory UI topo higlighter factory to register
+     */
+    default void register(UiTopoHighlighterFactory factory) {
+    }
+
+    /**
+     * Unregisters the specified user interface extension.
+     *
+     * @param factory UI topo higlighter factory to unregister
+     */
+    default void unregister(UiTopoHighlighterFactory factory) {
+    }
+
+    /**
      * Returns the list of registered user interface extensions.
      *
      * @return list of extensions
@@ -80,6 +96,15 @@
     }
 
     /**
+     * Returns the list of registered topo highlighter factories.
+     *
+     * @return list of highlighter factories
+     */
+    default List<UiTopoHighlighterFactory> getTopoHighlighterFactories() {
+        return new ArrayList<UiTopoHighlighterFactory>();
+    }
+
+    /**
      * Returns the navigation pane localization bundle.
      *
      * @return the navigation localization bundle