code: private Class<?> getButtonClass(ButtonType type) {
  		switch (type) {
  		case ACCOUNT_LINK:
  			return LoginButton.class;
  		case ACCOUNT_UNLINK:
  			return LogoutButton.class;
  		case ELEMENT_SHARE:
  			return ShareButton.class;
  		case PAYMENT:
  			return BuyButton.class;
  		case PHONE_NUMBER:
  			return PostbackButton.class;
  		case POSTBACK:
  			return PostbackButton.class;
  		case WEB_URL:
  			return WebUrlButton.class;
  		case NESTED:
  			return CallToActionNested.class;
  		}
  		// This will never happen.
  		return null;
  	}
docs: Utility method for getting a button class from the {@link ButtonType}.
  
  @param type
  the button type.
  @return the button class for that type.