Add additional tests

immutables/src/main/java/com/baeldung/immutable/ValueObject.java

@@ -2,5 +2,7 @@ package com.baeldung.immutable;
 
 public class ValueObject {
     public ValueObject() {
+
+
     }
 }

immutables/src/main/java/com/baeldung/immutable/auxiliary/Person.java

@@ -0,0 +1,13 @@
+package com.baeldung.immutable.auxiliary;
+
+
+import org.immutables.value.Value;
+
+@Value.Immutable
+public abstract class Person {
+    abstract String getName();
+    abstract Integer getAge();
+
+    @Value.Auxiliary
+    abstract String getAuxiliaryField();
+}