Apply JUnit4 style test

Change-Id: I16a639dbf5f9dd7f08068cf94312e5d04cb8776a
diff --git a/apps/dhcp/src/test/java/org/onosproject/dhcp/IpAssignmentTest.java b/apps/dhcp/src/test/java/org/onosproject/dhcp/IpAssignmentTest.java
index dad5ef5..3ecc5cf 100644
--- a/apps/dhcp/src/test/java/org/onosproject/dhcp/IpAssignmentTest.java
+++ b/apps/dhcp/src/test/java/org/onosproject/dhcp/IpAssignmentTest.java
@@ -16,7 +16,6 @@
 package org.onosproject.dhcp;
 
 import com.google.common.testing.EqualsTester;
-import junit.framework.TestCase;
 import org.junit.Assert;
 import org.junit.Test;
 import org.onlab.packet.Ip4Address;
@@ -31,7 +30,7 @@
 /**
  * Unit Tests for IPAssignment class.
  */
-public class IpAssignmentTest extends TestCase {
+public class IpAssignmentTest {
 
     private final Date dateNow = new Date();
 
@@ -98,4 +97,4 @@
             Assert.assertThat(e.getMessage(), containsString("must be specified"));
         }
     }
-}
\ No newline at end of file
+}
diff --git a/core/api/src/test/java/org/onosproject/store/service/DatabaseUpdateTest.java b/core/api/src/test/java/org/onosproject/store/service/DatabaseUpdateTest.java
index b498c1c..ad439d6 100644
--- a/core/api/src/test/java/org/onosproject/store/service/DatabaseUpdateTest.java
+++ b/core/api/src/test/java/org/onosproject/store/service/DatabaseUpdateTest.java
@@ -16,7 +16,6 @@
 package org.onosproject.store.service;
 
 import com.google.common.testing.EqualsTester;
-import junit.framework.TestCase;
 import org.junit.Test;
 
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -26,7 +25,7 @@
  * Unit Tests for DatabseUpdate class.
  */
 
-public class DatabaseUpdateTest extends TestCase {
+public class DatabaseUpdateTest {
 
     private final DatabaseUpdate stats1 = DatabaseUpdate.newBuilder()
             .withCurrentValue("1".getBytes())
@@ -124,4 +123,4 @@
         assertThat(stats1.toString(), is(stats1.toString()));
     }
 
-}
\ No newline at end of file
+}
diff --git a/core/api/src/test/java/org/onosproject/store/service/MapEventTest.java b/core/api/src/test/java/org/onosproject/store/service/MapEventTest.java
index c241c0e..47fba6c 100644
--- a/core/api/src/test/java/org/onosproject/store/service/MapEventTest.java
+++ b/core/api/src/test/java/org/onosproject/store/service/MapEventTest.java
@@ -16,7 +16,6 @@
 package org.onosproject.store.service;
 
 import com.google.common.testing.EqualsTester;
-import junit.framework.TestCase;
 import org.junit.Test;
 
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -25,7 +24,7 @@
 /**
  * MapEvent unit tests.
  */
-public class MapEventTest extends TestCase {
+public class MapEventTest {
 
     private final Versioned<Integer> vStats = new Versioned<>(2, 1);
 
@@ -58,4 +57,4 @@
                 .testEquals();
     }
 
-}
\ No newline at end of file
+}
diff --git a/core/api/src/test/java/org/onosproject/store/service/MultiValuedTimestampTest.java b/core/api/src/test/java/org/onosproject/store/service/MultiValuedTimestampTest.java
index 5d991a2..43475e4 100644
--- a/core/api/src/test/java/org/onosproject/store/service/MultiValuedTimestampTest.java
+++ b/core/api/src/test/java/org/onosproject/store/service/MultiValuedTimestampTest.java
@@ -16,7 +16,6 @@
 package org.onosproject.store.service;
 
 import com.google.common.testing.EqualsTester;
-import junit.framework.TestCase;
 
 import org.junit.Assert;
 import org.junit.Test;
@@ -31,7 +30,7 @@
 /**
  * MultiValuedTimestamp unit tests.
  */
-public class MultiValuedTimestampTest extends TestCase {
+public class MultiValuedTimestampTest {
 
     private final MultiValuedTimestamp<Integer, Integer> stats1 = new MultiValuedTimestamp<>(1, 3);
 
@@ -91,4 +90,4 @@
             Assert.fail("Exception looking up constructors");
         }
     }
-}
\ No newline at end of file
+}
diff --git a/core/api/src/test/java/org/onosproject/store/service/VersionedTest.java b/core/api/src/test/java/org/onosproject/store/service/VersionedTest.java
index 8a401db..fbe3271 100644
--- a/core/api/src/test/java/org/onosproject/store/service/VersionedTest.java
+++ b/core/api/src/test/java/org/onosproject/store/service/VersionedTest.java
@@ -16,7 +16,6 @@
 package org.onosproject.store.service;
 
 import com.google.common.testing.EqualsTester;
-import junit.framework.TestCase;
 import org.junit.Test;
 
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -25,7 +24,7 @@
 /**
  * Versioned unit tests.
  */
-public class VersionedTest extends TestCase {
+public class VersionedTest {
 
     private final Versioned<Integer> stats1 = new Versioned<>(1, 2, 3);
 
diff --git a/utils/misc/src/test/java/org/onlab/util/HexStringTest.java b/utils/misc/src/test/java/org/onlab/util/HexStringTest.java
index 2765212..e04e29a 100644
--- a/utils/misc/src/test/java/org/onlab/util/HexStringTest.java
+++ b/utils/misc/src/test/java/org/onlab/util/HexStringTest.java
@@ -21,12 +21,14 @@
 
 import junit.framework.TestCase;
 
+import static org.junit.Assert.fail;
+
 /**
  * Test of the Hexstring.
  *
  */
 
-public class HexStringTest extends TestCase {
+public class HexStringTest {
 
     @Test
     public void testMarshalling() throws Exception {