Make Pair class immutable when user supplies immutable objects

- Make fields private
- Add getters

Change-Id: I4bdc63316e21a88f9026cd42e424bf94873d02bb
diff --git a/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java b/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java
index 05510f6..68da549 100644
--- a/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java
+++ b/src/main/java/net/onrc/onos/core/flowprogrammer/FlowPusher.java
@@ -644,7 +644,7 @@
             Collection<Pair<IOFSwitch, FlowEntry>> entries, MsgPriority priority) {
 
         for (Pair<IOFSwitch, FlowEntry> entry : entries) {
-            add(entry.first, entry.second, priority);
+            add(entry.getFirst(), entry.getSecond(), priority);
         }
     }