ONOS-4971: Synthetic Link Data -- WIP

- adding CLI commands for dumping Model Cache contents.

Change-Id: I28dfe179835de6cd0c5356faf87af46a239eb772
diff --git a/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopology.java b/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopology.java
index b4eabe9..585e658 100644
--- a/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopology.java
+++ b/core/api/src/main/java/org/onosproject/ui/model/topo/UiTopology.java
@@ -261,6 +261,15 @@
     }
 
     /**
+     * Returns all links in the model.
+     *
+     * @return all links
+     */
+    public Set<UiLink> allLinks() {
+        return new HashSet<>(linkLookup.values());
+    }
+
+    /**
      * Returns the link with the specified identifier, or null if no such
      * link exists.
      *
@@ -302,6 +311,15 @@
     }
 
     /**
+     * Returns all hosts in the model.
+     *
+     * @return all hosts
+     */
+    public Set<UiHost> allHosts() {
+        return new HashSet<>(hostLookup.values());
+    }
+
+    /**
      * Returns the host with the specified identifier, or null if no such
      * host exists.
      *