public static function get_definition_sharing_options($sharingoption, $isselectedoptions = true) {
        $options = array();
        $prefix = ($isselectedoptions) ? 'sharingselected' : 'sharing';
        if ($sharingoption & cache_definition::SHARING_ALL) {
            $options[cache_definition::SHARING_ALL] = new lang_string($prefix.'_all', 'cache');
        }
        if ($sharingoption & cache_definition::SHARING_SITEID) {
            $options[cache_definition::SHARING_SITEID] = new lang_string($prefix.'_siteid', 'cache');
        }
        if ($sharingoption & cache_definition::SHARING_VERSION) {
            $options[cache_definition::SHARING_VERSION] = new lang_string($prefix.'_version', 'cache');
        }
        if ($sharingoption & cache_definition::SHARING_INPUT) {
            $options[cache_definition::SHARING_INPUT] = new lang_string($prefix.'_input', 'cache');
        }
        return $options;
    }