Added application ID store; both trivial and distributed variants.
diff --git a/cli/src/main/java/org/onlab/onos/cli/Comparators.java b/cli/src/main/java/org/onlab/onos/cli/Comparators.java
index 807af27..80b31d5 100644
--- a/cli/src/main/java/org/onlab/onos/cli/Comparators.java
+++ b/cli/src/main/java/org/onlab/onos/cli/Comparators.java
@@ -18,6 +18,7 @@
  */
 package org.onlab.onos.cli;
 
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.cluster.ControllerNode;
 import org.onlab.onos.net.Element;
 import org.onlab.onos.net.ElementId;
@@ -36,6 +37,13 @@
     private Comparators() {
     }
 
+    public static final Comparator<ApplicationId> APP_ID_COMPARATOR = new Comparator<ApplicationId>() {
+        @Override
+        public int compare(ApplicationId id1, ApplicationId id2) {
+            return id1.id() - id2.id();
+        }
+    };
+
     public static final Comparator<ElementId> ELEMENT_ID_COMPARATOR = new Comparator<ElementId>() {
         @Override
         public int compare(ElementId id1, ElementId id2) {