Code cleanup (#1461)

* Code cleanup

* Fix flux tests

* Fix checkstyle errors

* Fix compile error

unit-of-work/README.md

@@ -79,8 +79,8 @@ public interface IUnitOfWork<T> {
 public class StudentRepository implements IUnitOfWork<Student> {
   private static final Logger LOGGER = LoggerFactory.getLogger(StudentRepository.class);
 
-  private Map<String, List<Student>> context;
-  private StudentDatabase studentDatabase;
+  private final Map<String, List<Student>> context;
+  private final StudentDatabase studentDatabase;
 
   public StudentRepository(Map<String, List<Student>> context, StudentDatabase studentDatabase) {
     this.context = context;

unit-of-work/src/main/java/com/iluwatar/unitofwork/StudentRepository.java

@@ -35,8 +35,8 @@ import org.slf4j.LoggerFactory;
 public class StudentRepository implements IUnitOfWork<Student> {
   private static final Logger LOGGER = LoggerFactory.getLogger(StudentRepository.class);
 
-  private Map<String, List<Student>> context;
-  private StudentDatabase studentDatabase;
+  private final Map<String, List<Student>> context;
+  private final StudentDatabase studentDatabase;
 
   /**
    * Constructor.