public static function contact($atts = array())
 {
     $all_defaults = Footer_Credits_Options::get_defaults();
     $defaults = array();
     $defaults['show_telephone'] = $all_defaults['show_telephone'];
     $defaults['show_email'] = $all_defaults['show_email'];
     $defaults['show_address'] = $all_defaults['show_address'];
     $defaults['use_microdata'] = $all_defaults['use_microdata'];
     $defaults['separator'] = $all_defaults['separator'];
     $defaults['item_separator'] = $all_defaults['item_separator'];
     $defaults['section_separator'] = $all_defaults['section_separator'];
     $defaults['footer_class'] = self::CODE;
     $params = shortcode_atts($defaults, $atts);
     //apply plugin defaults
     return sprintf('<span class="%1$s">%2$s</span>', $params['footer_class'], self::contact_info($params));
 }