diff --git a/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonempty/ReturnFirstNonEmptyOptionalUnitTest.java b/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonempty/ReturnFirstNonEmptyOptionalUnitTest.java
index c432af6591..4686692215 100644
--- a/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonempty/ReturnFirstNonEmptyOptionalUnitTest.java
+++ b/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonempty/ReturnFirstNonEmptyOptionalUnitTest.java
@@ -19,7 +19,7 @@ public class ReturnFirstNonEmptyOptionalUnitTest {
     }
 
     @Test
-    public void givenListOfOptionals_thenReturnFirstNonEmpty() {
+    void givenListOfOptionals_thenReturnFirstNonEmpty() {
         Optional<String> object = optionals.stream()
             .filter(Optional::isPresent)
             .map(Optional::get)
diff --git a/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullLazyEvaluateUnitTest.java b/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullLazyEvaluateUnitTest.java
index f6bf6adbdc..649e5f4299 100644
--- a/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullLazyEvaluateUnitTest.java
+++ b/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullLazyEvaluateUnitTest.java
@@ -13,15 +13,13 @@ import java.util.stream.Stream;
 import org.apache.commons.lang3.ObjectUtils;
 import org.junit.jupiter.api.Test;
 import org.mockito.Mockito;
-import org.mockito.Spy;
 
 public class ReturnFirstNonNullLazyEvaluateUnitTest {
 
-    @Spy
     private final LazyEvaluate spy = Mockito.spy(new LazyEvaluate());
 
     @Test
-    public void givenChainOfMethods_thenLazilyEvaluateMethodsUntilFirstNonNull() {
+    void givenChainOfMethods_thenLazilyEvaluateMethodsUntilFirstNonNull() {
         String object = spy.methodA();
         if (object == null) {
             object = spy.methodB();
@@ -38,7 +36,7 @@ public class ReturnFirstNonNullLazyEvaluateUnitTest {
     }
 
     @Test
-    public void givenChainOfMethods_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
+    void givenChainOfMethods_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
         String object = ObjectUtils.getFirstNonNull(spy::methodA, spy::methodB, spy::methodC);
 
         assertEquals("first non null", object);
@@ -48,7 +46,7 @@ public class ReturnFirstNonNullLazyEvaluateUnitTest {
     }
 
     @Test
-    public void givenChainOfMethods_whenUsingSupplierInterface_thenLazilyEvaluateMethodsUntilFirstNonNull() {
+    void givenChainOfMethods_whenUsingSupplierInterface_thenLazilyEvaluateMethodsUntilFirstNonNull() {
         Optional<String> object = Stream.<Supplier<String>> of(spy::methodA, spy::methodB, spy::methodC)
             .map(Supplier::get)
             .filter(Objects::nonNull)
@@ -61,7 +59,7 @@ public class ReturnFirstNonNullLazyEvaluateUnitTest {
     }
 
     @Test
-    public void givenNonNullObjectAndFallbackMethod_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
+    void givenNonNullObjectAndFallbackMethod_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
         String nonNullObject = spy.methodB();
         String object = ObjectUtils.getIfNull(nonNullObject, spy::methodC);
 
@@ -70,7 +68,7 @@ public class ReturnFirstNonNullLazyEvaluateUnitTest {
     }
 
     @Test
-    public void givenNullObjectAndFallbackMethod_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
+    void givenNullObjectAndFallbackMethod_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
         String nullObject = null;
         String object = ObjectUtils.getIfNull(nullObject, spy::methodB);
 
diff --git a/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullUnitTest.java b/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullUnitTest.java
index f99a8cb419..aae775997d 100644
--- a/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullUnitTest.java
+++ b/core-java-modules/core-java-lang-6/src/test/java/com/baeldung/returnfirstnonnull/ReturnFirstNonNullUnitTest.java
@@ -26,7 +26,7 @@ public class ReturnFirstNonNullUnitTest {
     }
 
     @Test
-    public void givenListOfObjects_whenFilterIsLambdaNullCheck_thenReturnFirstNonNull() {
+    void givenListOfObjects_whenFilterIsLambdaNullCheck_thenReturnFirstNonNull() {
         Optional<String> object = objects.stream()
             .filter(o -> o != null)
             .findFirst();
@@ -35,7 +35,7 @@ public class ReturnFirstNonNullUnitTest {
     }
 
     @Test
-    public void givenListOfObjects_whenFilterIsMethodRefNullCheck_thenReturnFirstNonNull() {
+    void givenListOfObjects_whenFilterIsMethodRefNullCheck_thenReturnFirstNonNull() {
         Optional<String> object = objects.stream()
             .filter(Objects::nonNull)
             .findFirst();
@@ -44,7 +44,7 @@ public class ReturnFirstNonNullUnitTest {
     }
 
     @Test
-    public void givenListOfObjects_whenIteratingWithForLoop_thenReturnFirstNonNull() {
+    void givenListOfObjects_whenIteratingWithForLoop_thenReturnFirstNonNull() {
         String object = null;
         for (int i = 0; i < objects.size(); i++) {
             if (objects.get(i) != null) {
@@ -57,21 +57,21 @@ public class ReturnFirstNonNullUnitTest {
     }
 
     @Test
-    public void givenListOfObjects_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
+    void givenListOfObjects_whenUsingApacheCommonsLang3_thenReturnFirstNonNull() {
         String object = ObjectUtils.firstNonNull(objects.toArray(new String[0]));
 
         assertEquals("first non null", object);
     }
 
     @Test
-    public void givenListOfObjects_whenUsingGoogleGuavaIterables_thenReturnFirstNonNull() {
+    void givenListOfObjects_whenUsingGoogleGuavaIterables_thenReturnFirstNonNull() {
         String object = Iterables.find(objects, Predicates.notNull());
 
         assertEquals("first non null", object);
     }
 
     @Test
-    public void givenTwoObjects_whenUsingGoogleGuavaMoreObjects_thenReturnFirstNonNull() {
+    void givenTwoObjects_whenUsingGoogleGuavaMoreObjects_thenReturnFirstNonNull() {
         String nullObject = null;
         String nonNullObject = "first non null";
         String object = MoreObjects.firstNonNull(nullObject, nonNullObject);