Finished after code review and added into the build-all.sh script

build-all.sh

@@ -86,6 +86,7 @@ if [[ "$MODULE" == "module6" ]]
 then
   # ADD NEW MODULES HERE
   # (add new modules above the rest so you get quicker feedback if it fails)
+  build_maven_module "immutables"
   build_maven_module "core-java/versions"
   build maven_module "java-hashes"
   build maven_module "http-clients"

immutables/src/main/java/com/reflectoring/io/immutables/optionalAndDefault/DefaultArticleInterface.java

@@ -0,0 +1,17 @@
+package com.reflectoring.io.immutables.optionalAndDefault;
+
+import org.immutables.value.Value;
+
+@Value.Immutable
+interface DefaultArticleInterface {
+
+    Long getId();
+
+    @Value.Default
+    default String getTitle(){
+        return "Default title!";
+    }
+
+    String getContent();
+
+}

immutables/src/main/java/com/reflectoring/io/immutables/optionalAndDefault/OptionalAndDefaultService.java

@@ -8,10 +8,16 @@ public class OptionalAndDefaultService {
         OptionalArticle article =  ImmutableOptionalArticle.builder().build();
         DefaultArticle defaultArticle = ImmutableDefaultArticle.builder()
                 .id(0l)
-                .content("Lorem ipsum content!")
+                .content("Lorem ipsum!")
                 .build();
 
-        System.out.println(article);
+        DefaultArticleInterface defaultArticleInterface =
+                ImmutableDefaultArticleInterface.builder()
+                        .id(0l)
+                        .content("Lorem ipsum!")
+                        .build();
+
         System.out.println(defaultArticle);
+        System.out.println(defaultArticleInterface);
     }
 }