def framesToFrameRange(frames, sort=True, zfill=0, compress=False):
        if compress:
            frames = unique(set(), frames)
        frames = list(frames)
        if not frames:
            return ''
        if len(frames) == 1:
            return pad(frames[0], zfill)
        if sort:
            frames.sort()
        return ','.join(FrameSet.framesToFrameRanges(frames, zfill))