: close === ']'
                ? endEscape.length % 2 === 0
                    // A normal case, and it is a range notation
                    // '[bar]'
                    // '[bar\\\\]'
                    ? `[${sanitizeRange(range)}${endEscape}]`
                    // Invalid range notaton
                    // '[bar\\]' -> '[bar\\\\]'
                    : '[]'
                : '[]'
    ],