@Override
protected Iterable<? extends ProcessingStep> initSteps() {
Filer filer = new FormattingFiler(processingEnv.getFiler());
Messager messager = processingEnv.getMessager();
Elements elements = processingEnv.getElementUtils();
Types types = processingEnv.getTypeUtils();
return ImmutableList.of(
new AndroidMapKeyValidator(elements, types, messager),
new ContributesAndroidInjectorGenerator(
new AndroidInjectorDescriptor.Validator(types, elements, messager),
useStringKeys(),
filer,
elements,
processingEnv.getSourceVersion()));
}