Fix for ONOS-5032 and ONOS-5034

Change-Id: Ib964252dd05754ce7069a7a82ccb1d1c29bfa978
diff --git a/core/api/src/main/java/org/onosproject/net/Host.java b/core/api/src/main/java/org/onosproject/net/Host.java
index b9621b7..485b76f 100644
--- a/core/api/src/main/java/org/onosproject/net/Host.java
+++ b/core/api/src/main/java/org/onosproject/net/Host.java
@@ -18,6 +18,7 @@
 import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
+import org.onosproject.store.service.WallClockTimestamp;
 
 import java.util.Set;
 
@@ -63,6 +64,14 @@
      */
     HostLocation location();
 
+    /**
+     * Returns the host recent time.
+     * @return host last updated time
+     */
+    default WallClockTimestamp timestamp() {
+        return null;
+    }
     // TODO: explore capturing list of recent locations to aid in mobility
 
 }
+