function has_valid( $key, $expiration = null ) {
            $cache_entry = $this->_options->get_option( $key, false );

            $is_valid = ( is_object( $cache_entry ) &&
                          isset( $cache_entry->timestamp ) &&
                          is_numeric( $cache_entry->timestamp ) &&
                          $cache_entry->timestamp > WP_FS__SCRIPT_START_TIME
            );

            if ( $is_valid &&
                 is_numeric( $expiration ) &&
                 isset( $cache_entry->created ) &&
                 is_numeric( $cache_entry->created ) &&
                 $cache_entry->created + $expiration < WP_FS__SCRIPT_START_TIME
            ) {
                /**
                 * Even if the cache is still valid, since we are checking for validity
                 * with an explicit expiration period, if the period has past, return
                 * `false` as if the cache is invalid.
                 *
                 * @since 1.2.2.7
                 */
                $is_valid = false;
            }

            return $is_valid;
        }