Jetpack_Sync_Settings::is_importing PHP Method

    static function is_importing()
    {
        if (!is_null(self::$is_importing)) {
            return self::$is_importing;
        }
        return defined('WP_IMPORTING') && WP_IMPORTING;
    }

 static function set_importing($is_importing)
 {
     // set to NULL to revert to WP_IMPORTING, the standard behaviour
     self::$is_importing = $is_importing;
 }