code: protected Label newButtonLabel(final String id, final String resourceKey,
  		final String defaultValue)
  	{
  		final IModel<String> labelModel = ResourceModelFactory.newResourceModel(resourceKey, this,
  			defaultValue);
  
  		return ComponentFactory.newLabel(id, labelModel);
  	}
docs: Factory method for creating the new {@link Label} for the button. This method is invoked in
  the constructor from the derived classes and can be overridden so users can provide their own
  version of a new {@link Label} for the button.
  
  @param id
  the id
  @param resourceKey
  the resource key
  @param defaultValue
  the default value
  @return the new {@link Label} for the button.