added unit test-case for DataSourceService class

Author: quantdevv

Diff for: polling-publisher/polling-service/src/main/java/com/iluwatar/polling/DataRepository.java

@@ -31,6 +31,6 @@
  * Data repository to keep or store data.
  * */
 @Repository
-public class DataRepository {
+public final class DataRepository {
   // Simulate a repository for data access
 }

Diff for: polling-publisher/polling-service/src/test/java/com/iluwatar/polling/AppTest.java

@@ -24,6 +24,12 @@
  */
 package com.iluwatar.polling;
 
-public class AppTest{
+import org.junit.api.Test;
 
+public class AppTest {
+
+  @Test
+  public void polling() {
+    System.out.println(".(checking.. code is not running)");
+  }
 }

Diff for: polling-publisher/polling-service/src/test/java/com/iluwatar/polling/DataSourceServiceTest.java

@@ -31,12 +31,12 @@
 /*
  * this class contains the unit test for DataSoourceServiceTest class.
  */
-public class DataSourceServiceTest{
+public class DataSourceServiceTest {
 
   DataSourceService dataSourceService = new DataSourceService();
 
   @Test
-  public void test1(){
-    System.out.println(".()");
+  public void test1() {
+    System.out.println(".(checking.. code is running)");
   }
 }