/**
  * A image's state is simply the contatenation of two values: its retina setting and its path.
  *
  * This is used to determine whether the image is changed when the customizer's settings are saved.
  *
  * @see Crafted_Customizer::set_current_image_state()
  * @see Crafted_Customizer::is_image_changed()
  *
  * @return  string The state as a simple string.
  * @access  private
  * @since   1.0.0
  */
 private function get_image_state()
 {
     return $this->theme->get_theme_setting($this->id . '_is_retina', false) . '_' . $this->theme->get_theme_setting($this->id, false);
 }