Add oving 2

src/test/java/oving2/TestHelper.java

@@ -0,0 +1,15 @@
+package oving2;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+public class TestHelper {
+
+    public static void checkIfFieldsPrivate(Class<?> clazz) {
+        for (Field field : clazz.getDeclaredFields()) {
+            assertTrue(Modifier.isPrivate(field.getModifiers()),
+                    "Expected field " + field.getName() + " to be private!");
+        }
+    }
+}