📍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>

private-class-data/README.md

@@ -37,8 +37,8 @@ Taking our stew example from above. First we have a `Stew` class where its data
 private class data, making the stew's ingredient mutable to class methods. 
 
 ```java
+@Slf4j
 public class Stew {
-  private static final Logger LOGGER = LoggerFactory.getLogger(Stew.class);
   private int numPotatoes;
   private int numCarrots;
   private int numMeat;
@@ -99,8 +99,8 @@ public class StewData {
     return numPeppers;
   }
 }
+@Slf4j
 public class ImmutableStew {
-  private static final Logger LOGGER = LoggerFactory.getLogger(ImmutableStew.class);
   private final StewData data;
   public ImmutableStew(int numPotatoes, int numCarrots, int numMeat, int numPeppers) {
     data = new StewData(numPotatoes, numCarrots, numMeat, numPeppers);