def _dqdir(self, jobdir):
        """ Return a folder name to keep disk queue state at """
        if jobdir:
            dqdir = join(jobdir, 'requests.queue')
            if not exists(dqdir):
                os.makedirs(dqdir)
            return dqdir
 Return a folder name to keep disk queue state at 
stackoverflow/venv/lib/python3.6/site-packages/scrapy/core/scheduler.py