Unit Test Cases For YANG Io

Change-Id: Ie8876c25e4a293c52ae4c135921b7fe168f5f7c1
diff --git a/utils/yangutils/src/test/java/org/onosproject/yangutils/utils/UtilConstantsTest.java b/utils/yangutils/src/test/java/org/onosproject/yangutils/utils/UtilConstantsTest.java
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+++ b/utils/yangutils/src/test/java/org/onosproject/yangutils/utils/UtilConstantsTest.java
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+/*
+ * Copyright 2016 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.yangutils.utils;
+
+import org.junit.Test;
+import org.junit.Rule;
+import org.junit.rules.ExpectedException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * Test case for testing the util constants.
+ */
+public final class UtilConstantsTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * A private constructor is tested.
+     *
+     * @throws SecurityException if any security violation is observed.
+     * @throws NoSuchMethodException if when the method is not found.
+     * @throws IllegalArgumentException if there is illegal argument found.
+     * @throws InstantiationException if instantiation is provoked for the private constructor.
+     * @throws IllegalAccessException if instance is provoked or a method is provoked.
+     * @throws InvocationTargetException when an exception occurs by the method or constructor.
+     */
+    @Test
+    public void callPrivateConstructors() throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+    InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {UtilConstants.class};
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertNotNull(constructor.newInstance());
+        }
+    }
+}
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