@Value.Lazy
	public NameForms typeBuilder() {
		InnerBuilderDefinition innerBuilder = innerBuilder();
		if (innerBuilder.isExtending) {
			NameForms typeAbstract = typeAbstract();
			return ImmutableConstitution.NameForms.copyOf(typeAbstract)
					.withRelativeRaw(DOT_JOINER.join(typeAbstract.relativeRaw(), innerBuilder.simpleName))
					.withSimple(innerBuilder.simpleName);
		}
		return typeImplementationBuilder();
	}
Walks to the enclosing type's simple names and applies naming convention.
This shortcut/fix shows deficiency of model (it's probably more complicated than needed).
@return enclosing immutable name
value-processor/src/org/immutables/value/processor/meta/Constitution.java