@Override
    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
      if (roundEnv.processingOver()) {
        typeUtils = processingEnv.getTypeUtils();
        elementUtils = processingEnv.getElementUtils();
        test();
      }
      return false;
    }
Returns a "base type" for TypeSimplifier that does not contain any nested types. The point
being that every {@code TypeSimplifier} has a base type that the class being generated is going
to extend, and if that class has nested types they will be in scope, and therefore a possible
source of ambiguity.
value/src/test/java/com/google/auto/value/processor/TypeEncoderTest.java