def show_title(decorated)
      raise ::ArgumentError unless decorated.is_a? ResourceDecorator
      [
        to_model_label(decorated.model_class), decorated.to_label
      ].compact.join ': '
    end
def show_title(decorated)
      raise ::ArgumentError unless decorated.is_a? ResourceDecorator
      [
        to_model_label(decorated.model_class), decorated.to_label
      ].compact.join ': '
    end
Title for show page of given resource
 @param decorated [Wallaby::ResourceDecorator]
 @return [String]