ONOS-2186 - GUI Topo Overlay - (WIP)
- Showing traffic on selected intent now subdues other elements.
- Augmented Highlights to allow for retrieval by ID.
- Reparented HostHighlight and DeviceHighlight to NodeHighlight.
- Added a few extra highlight unit tests.

Change-Id: I0de1cefdcfda58a6fec6e90be5fe898d35aa1b37
diff --git a/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoJson.java b/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoJson.java
index 0a12e1c..8b4b354 100644
--- a/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoJson.java
+++ b/web/gui/src/main/java/org/onosproject/ui/impl/topo/TopoJson.java
@@ -90,13 +90,13 @@
     }
 
     private static ObjectNode json(DeviceHighlight dh) {
-        // TODO: implement this once we know what a device highlight looks like
-        return objectNode();
+        return objectNode()
+                .put(ID, dh.elementId());
     }
 
     private static ObjectNode json(HostHighlight hh) {
-        // TODO: implement this once we know what a host highlight looks like
-        return objectNode();
+        return objectNode()
+                .put(ID, hh.elementId());
     }
 
     private static ObjectNode json(LinkHighlight lh) {