def on_box(params = {})
      box = Yummi::TextBox::new params
      box.add self
      return box
    end
def on_box(params = {})
      box = Yummi::TextBox::new params
      box.add self
      return box
    end
Returns the string wrapped in a #Yummi#TextBox. The given parameters will be used
 to instantiate the TextBox.