[BAEL-6535] hydration of object examples (#15421)

Co-authored-by: Bhaskar <bhaskar.dastidar@freshworks.com>

libraries-data/src/test/java/com/baeldung/objecthydration/HydrationUnitTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.objecthydration;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class HydrationUnitTest {
+
+    @Test
+    public void givenEmptyClass_whenLazilyinitialised_thenGiveNullOnGet() {
+        User iamUser = new User();
+        Assert.assertNull(iamUser.getuId());
+    }
+
+    @Test
+    public void givenInitialisedClass_withLazilyInitialised_thenDoesNotGiveNullOnGet() {
+        User iamUser = new User();
+        iamUser.setAlias("007");
+        Assert.assertNotNull(iamUser.getAlias());
+    }
+
+    @Test
+    public void givenEmptyClass_withHydration_thenShouldHaveAllAttributesSet() {
+        User jamesBond = new User();
+        Assert.assertNull(jamesBond.getAlias());
+
+        jamesBond.generateMyUser();
+        Assert.assertEquals("007", jamesBond.getAlias());
+    }
+
+    @Test
+    public void givenUser_thenShouldPerformUserSerialisationDeserialisation() {
+        User iamUser = new User();
+        iamUser.setAlias("007");
+        UserSerialisationDeserialisation usd = new UserSerialisationDeserialisation();
+        usd.serialisedUser(iamUser, "bond.ser");
+        User deserialisedUser = usd.deserialiseUser("bond.ser");
+        Assert.assertEquals(iamUser.getAlias(), deserialisedUser.getAlias());
+
+    }
+}