@SuppressWarnings("CheckReturnValue")
  void use() {
    EnclosingFactory.HiddenImplementationBuilder.create().build();

    // Type name suffix was added to avoid name clashing
    EnclosingFactory.singletonInstanceHiddenImplementation();
    EnclosingFactory.singletonInstanceNonexposedImplementation();
    // Strictly follows naming template
    EnclosingFactory.newNonexposedImplementation(Optional.of(11));
    // Implementation is visible
    EnclosingFactory.newVisibleImplementation(Optional.<Integer>absent());
  }
Feature combination
<ul>
<li>Nested hidded implementation
<li>Defaults mechanism, implementation style override
<li>Style meta-annotation usage to create style
<li>Forwarding factory methods with names customization and auto-disambiguation
</ul>
value-fixture/src/org/immutables/fixture/style/EnclosingHiddenImplementation.java