Check if not null in the constructor

Change-Id: I5e73660004e5bb8e9e3c5ba6b02d1070ee977c22
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java b/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java
index 3a1d4f2..389a7be 100644
--- a/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java
@@ -757,7 +757,7 @@
         private int installAttempt;
 
         public IntentInstallMonitor(IntentOperations ops) {
-            this.ops = ops;
+            this.ops = checkNotNull(ops);
             resetTimeoutLimit();
         }