[ONOS-3251] Add the junit test code of SecurityGroup

Change-Id: If436b5e5e7acaed422794bf53a3b2e1d9da18695

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.vtnrsc.virtualport;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+import org.junit.Test;
+import org.onosproject.vtnrsc.SecurityGroup;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Unit tests for SecurityGroup class.
+ */
+public class SecurityGroupTest {
+
+    final SecurityGroup securityGroup1 = SecurityGroup.securityGroup("1");
+    final SecurityGroup sameAssecurityGroup = SecurityGroup.securityGroup("1");
+    final SecurityGroup securityGroup2 = SecurityGroup.securityGroup("2");
+
+    /**
+     * Checks that the SecurityGroup class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(SecurityGroup.class);
+    }
+
+    /**
+     * Checks the operation of equals().
+     */
+    @Test
+    public void testEquals() {
+        new EqualsTester().addEqualityGroup(securityGroup1, sameAssecurityGroup)
+                .addEqualityGroup(securityGroup2).testEquals();
+    }
+
+    /**
+     * Checks the construction of a SecurityGroup object.
+     */
+    @Test
+    public void testConstruction() {
+        final String securityGroupValue = "1";
+        final SecurityGroup securityGroup = SecurityGroup.securityGroup(securityGroupValue);
+        assertThat(securityGroup, is(notNullValue()));
+        assertThat(securityGroup.securityGroup(), is(securityGroupValue));
+
+    }
+}