/**
  * Assemble the list of icon types without MLA filtering
  *
  * @since 1.40
  *
  * @return	boolean	Success (true) or failure (false) of the operation
  */
 private static function _get_core_icon_types()
 {
     global $wp_filter;
     if (NULL != self::$mla_core_icon_types) {
         return true;
     }
     /*
      * wp_ext2type will apply our filter in a special mode, initializing the list
      */
     self::$disable_mla_filtering = true;
     $save_filters = $wp_filter['ext2type'];
     unset($wp_filter['ext2type']);
     add_filter('ext2type', 'MLAMime::mla_ext2type_filter', 0x7fffffff, 1);
     wp_ext2type('xxx');
     $wp_filter['ext2type'] = $save_filters;
     self::$disable_mla_filtering = false;
     /*
      * Rebuild the list as extension => type,
      * Explode any entries with multiple extensions
      */
     $standard_types = array();
     foreach (self::$mla_core_icon_types as $key => $extensions) {
         foreach ($extensions as $extension) {
             $standard_types[$extension] = $key;
         }
     }
     ksort($standard_types);
     self::$mla_core_icon_types = $standard_types;
     return true;
 }