iluwatar#348 - Data Tranfer Object : Make private varialbes final in immutalbe model.

Author: Gopinath Langote

data-transfer-object/src/main/java/com/iluwatar/datatransfer/CustomerDto.java

@@ -31,9 +31,9 @@
  * Dto will not have any business logic in it.
  */
 public class CustomerDto {
-  private String id;
-  private String firstName;
-  private String lastName;
+  private final String id;
+  private final String firstName;
+  private final String lastName;
 
   /**
    * @param id        customer id