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

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

interpreter/src/test/java/com/iluwatar/interpreter/ExpressionTest.java

@@ -102,7 +102,7 @@ public abstract class ExpressionTest<E extends Expression> {
    */
   @ParameterizedTest
   @MethodSource("expressionProvider")
-  public void testInterpret(NumberExpression first, NumberExpression second, int result) {
+  void testInterpret(NumberExpression first, NumberExpression second, int result) {
     final var expression = factory.apply(first, second);
     assertNotNull(expression);
     assertEquals(result, expression.interpret());
@@ -113,7 +113,7 @@ public abstract class ExpressionTest<E extends Expression> {
    */
   @ParameterizedTest
   @MethodSource("expressionProvider")
-  public void testToString(NumberExpression first, NumberExpression second) {
+  void testToString(NumberExpression first, NumberExpression second) {
     final var expression = factory.apply(first, second);
     assertNotNull(expression);
     assertEquals(expectedToString, expression.toString());

interpreter/src/test/java/com/iluwatar/interpreter/MinusExpressionTest.java

@@ -32,7 +32,7 @@ import org.junit.jupiter.params.provider.Arguments;
  *
  * @author Jeroen Meulemeester
  */
-public class MinusExpressionTest extends ExpressionTest<MinusExpression> {
+class MinusExpressionTest extends ExpressionTest<MinusExpression> {
 
   /**
    * Create a new set of test entries with the expected result

interpreter/src/test/java/com/iluwatar/interpreter/MultiplyExpressionTest.java

@@ -32,7 +32,7 @@ import org.junit.jupiter.params.provider.Arguments;
  *
  * @author Jeroen Meulemeester
  */
-public class MultiplyExpressionTest extends ExpressionTest<MultiplyExpression> {
+class MultiplyExpressionTest extends ExpressionTest<MultiplyExpression> {
 
   /**
    * Create a new set of test entries with the expected result

interpreter/src/test/java/com/iluwatar/interpreter/NumberExpressionTest.java

@@ -36,7 +36,7 @@ import org.junit.jupiter.params.provider.MethodSource;
  *
  * @author Jeroen Meulemeester
  */
-public class NumberExpressionTest extends ExpressionTest<NumberExpression> {
+class NumberExpressionTest extends ExpressionTest<NumberExpression> {
 
   /**
    * Create a new set of test entries with the expected result
@@ -60,7 +60,7 @@ public class NumberExpressionTest extends ExpressionTest<NumberExpression> {
    */
   @ParameterizedTest
   @MethodSource("expressionProvider")
-  public void testFromString(NumberExpression first) throws Exception {
+  void testFromString(NumberExpression first) throws Exception {
     final var expectedValue = first.interpret();
     final var testStringValue = String.valueOf(expectedValue);
     final var numberExpression = new NumberExpression(testStringValue);

interpreter/src/test/java/com/iluwatar/interpreter/PlusExpressionTest.java

@@ -32,7 +32,7 @@ import org.junit.jupiter.params.provider.Arguments;
  *
  * @author Jeroen Meulemeester
  */
-public class PlusExpressionTest extends ExpressionTest<PlusExpression> {
+class PlusExpressionTest extends ExpressionTest<PlusExpression> {
 
   /**
    * Create a new set of test entries with the expected result