/**
  * Saves the current mapping rule for term creation
  *
  * @since 2.20
  *
  * @param	array 	mapping rule
  * @param	integer post ID to be evaluated
  * @param	string 	category/scope to evaluate against: iptc_exif_standard_mapping, iptc_exif_taxonomy_mapping or iptc_exif_custom_mapping
  * @param	array 	attachment_metadata, default NULL
  */
 public static function mla_mapping_rule($setting_value, $post_id, $category, $attachment_metadata)
 {
     return self::$current_mapping_rule = $setting_value;
 }