braceExpand() {
        return braceExpand(this.pattern, this.options);
    }
/c)
                //     - b matches b
                //     - doublestar
                //       - matchOne(x/y/z/c, c) -> no
                //       - matchOne(y/z/c, c) -> no
                //       - matchOne(z/c, c) -> no
                //       - matchOne(c, c) yes, hit
                var fr = fi;
                var pr = pi + 1;
                if (pr === pl) {
                    this.debug('** at the end');
                    // a ** at the end will just swallow the rest.
                    // We have found a match.
                    // however, it will not swallow /.x, unless
                    // options.dot is set.
                    // . and .. are *never* matched by **, for explosively
                    // exponential reasons.
                    for (; fi < fl; fi++) {
                        if (file[fi] === '.' ||
                            file[fi] === '..' ||
                            (!options.dot && file[fi].charAt(0) === '.'))
                            return false;
                    }
                    return true;
                }
                // ok, let's see if we can swallow whatever we can.
                while (fr < fl) {
                    var swallowee = file[fr];
                    this.debug('\nglobstar while', file, fr, pattern, pr, swallowee);
                    // XXX remove this slice.  Just pass the start index.
                    if (this.matchOne(file.slice(fr), pattern.slice(pr), partial)) {
                        this.debug('globstar found match!', fr, fl, swallowee);
                        // found a match.
                        return true;
                    }
                    else {
                        // can't swallow "." or ".." ever.
                        // can only swallow ".foo" when explicitly asked.
                        if (swallowee === '.' ||
                            swallowee === '..' ||
                            (!options.dot && swallowee.charAt(0) === '.')) {
                            this.debug('dot detected!', file, fr, pattern, pr);
                            break;
                        }
                        // ** swallows a segment, and continue.
                        this.debug('globstar swallow a segment, and continue');
                        fr++;
                    }
                }
                // no match was found.
                // However, in partial mode, we can't say this is necessarily over.
                /* c8 ignore start