code: @SuppressWarnings("unchecked")
    @NonNull
    public final GenericType<? super T> getSupertype(@NonNull Class<? super T> superclass) {
      return new GenericType(token.getSupertype(superclass));
    }
docs: Returns the generic form of {@code superclass}. For example, if this is {@code
  ArrayList<String>}, {@code Iterable<String>} is returned given the input {@code
  Iterable.class}.