diff --git a/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/IPAddressTest.java b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/IPAddressTest.java
index 25fc943..865df75 100644
--- a/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/IPAddressTest.java
+++ b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/IPAddressTest.java
@@ -1,6 +1,9 @@
 package org.projectfloodlight.openflow.types;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.net.UnknownHostException;
 
 import org.junit.Test;
 
@@ -51,4 +54,14 @@
         }
     }
 
+    @Test
+    public void testFromInetAddressException() throws UnknownHostException {
+        try {
+            IPAddress.fromInetAddress(null);
+            fail("Should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertNotNull(e.getMessage());
+        }
+    }
+
 }