refactor: remove code smell java:S5786 (#2159)

https://sonarcloud.io/organizations/iluwatar/rules?open=java%3AS5786&rule_key=java%3AS5786

flux/src/test/java/com/iluwatar/flux/action/ContentTest.java

@@ -34,7 +34,7 @@ import org.junit.jupiter.api.Test;
  *
  * @author Jeroen Meulemeester
  */
-public class ContentTest {
+class ContentTest {
 
   @Test
   void testToString() {

flux/src/test/java/com/iluwatar/flux/action/MenuItemTest.java

@@ -34,7 +34,7 @@ import org.junit.jupiter.api.Test;
  *
  * @author Jeroen Meulemeester
  */
-public class MenuItemTest {
+class MenuItemTest {
 
   @Test
   void testToString() {

flux/src/test/java/com/iluwatar/flux/dispatcher/DispatcherTest.java

@@ -49,7 +49,7 @@ import org.mockito.ArgumentCaptor;
  *
  * @author Jeroen Meulemeester
  */
-public class DispatcherTest {
+class DispatcherTest {
 
   /**
    * Dispatcher is a singleton with no way to reset it's internal state back to the beginning.
@@ -57,7 +57,7 @@ public class DispatcherTest {
    * influence on each other.
    */
   @BeforeEach
-  public void setUp() throws Exception {
+  void setUp() throws Exception {
     final var constructor = Dispatcher.class.getDeclaredConstructor();
     constructor.setAccessible(true);
 

flux/src/test/java/com/iluwatar/flux/store/ContentStoreTest.java

@@ -44,7 +44,7 @@ import org.junit.jupiter.api.Test;
  *
  * @author Jeroen Meulemeester
  */
-public class ContentStoreTest {
+class ContentStoreTest {
 
   @Test
   void testOnAction() {

flux/src/test/java/com/iluwatar/flux/store/MenuStoreTest.java

@@ -44,7 +44,7 @@ import org.junit.jupiter.api.Test;
  *
  * @author Jeroen Meulemeester
  */
-public class MenuStoreTest {
+class MenuStoreTest {
 
   @Test
   void testOnAction() {

flux/src/test/java/com/iluwatar/flux/view/ContentViewTest.java

@@ -39,7 +39,7 @@ import org.junit.jupiter.api.Test;
  *
  * @author Jeroen Meulemeester
  */
-public class ContentViewTest {
+class ContentViewTest {
 
   @Test
   void testStoreChanged() {

flux/src/test/java/com/iluwatar/flux/view/MenuViewTest.java

@@ -43,7 +43,7 @@ import org.junit.jupiter.api.Test;
  *
  * @author Jeroen Meulemeester
  */
-public class MenuViewTest {
+class MenuViewTest {
 
   @Test
   void testStoreChanged() {