code: protected OptionHandler createOptionHandler(OptionDef o, Setter setter) {
          checkNonNull(o, "OptionDef");
          checkNonNull(setter, "Setter");
          return OptionHandlerRegistry.getRegistry().createOptionHandler(this, o, setter);
      }
docs: Creates an {@link OptionHandler} that handles the given {@link Option} annotation
  and the {@link Setter} instance.