Prohibit null for resources field in Intent

Change-Id: I128c6e63ccccaf817e83ff1c440a731fb98b42f7
diff --git a/core/api/src/test/java/org/onosproject/net/intent/TestInstallableIntent.java b/core/api/src/test/java/org/onosproject/net/intent/TestInstallableIntent.java
index 4c69bf3..32e5c90 100644
--- a/core/api/src/test/java/org/onosproject/net/intent/TestInstallableIntent.java
+++ b/core/api/src/test/java/org/onosproject/net/intent/TestInstallableIntent.java
@@ -17,6 +17,8 @@
 
 import org.onosproject.TestApplicationId;
 
+import java.util.Collections;
+
 /**
  * An installable intent used in the unit test.
  */
@@ -30,7 +32,7 @@
      * @param value intent ID
      */
     public TestInstallableIntent(int value) { // FIXME
-        super(new TestApplicationId("foo"), null);
+        super(new TestApplicationId("foo"), Collections.emptyList());
         this.value = value;
     }