📍Use lombok, reformat, and optimize the code (#1560)

* Use lombok, reformat, and optimize the code

* Fix merge conflicts and some sonar issues

Co-authored-by: va1m <va1m@email.com>

separated-interface/src/test/java/com/iluwatar/separatedinterface/invoice/InvoiceGeneratorTest.java

@@ -23,17 +23,20 @@
 
 package com.iluwatar.separatedinterface.invoice;
 
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-import static org.mockito.Mockito.*;
-
-public class InvoiceGeneratorTest {
+class InvoiceGeneratorTest {
 
   private InvoiceGenerator target;
 
   @Test
-  public void testGenerateTax() {
+  void testGenerateTax() {
     var productCost = 50.0;
     var tax = 10.0;
     TaxCalculator taxCalculatorMock = mock(TaxCalculator.class);

separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/DomesticTaxCalculatorTest.java

@@ -26,16 +26,16 @@ package com.iluwatar.separatedinterface.taxes;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-public class DomesticTaxCalculatorTest {
+class DomesticTaxCalculatorTest {
 
   private DomesticTaxCalculator target;
 
   @Test
-  public void testTaxCalculation(){
+  void testTaxCalculation() {
     target = new DomesticTaxCalculator();
 
-    var tax=target.calculate(100.0);
-    Assertions.assertEquals(tax,20.0);
+    var tax = target.calculate(100.0);
+    Assertions.assertEquals(tax, 20.0);
   }
 
 }

separated-interface/src/test/java/com/iluwatar/separatedinterface/taxes/ForeignTaxCalculatorTest.java

@@ -26,16 +26,16 @@ package com.iluwatar.separatedinterface.taxes;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-public class ForeignTaxCalculatorTest {
+class ForeignTaxCalculatorTest {
 
   private ForeignTaxCalculator target;
 
   @Test
-  public void testTaxCalculation(){
+  void testTaxCalculation() {
     target = new ForeignTaxCalculator();
 
-    var tax=target.calculate(100.0);
-    Assertions.assertEquals(tax,60.0);
+    var tax = target.calculate(100.0);
+    Assertions.assertEquals(tax, 60.0);
   }
 
 }