code: def waitForExists(self, jobStoreID, maxTries=35, sleepTime=1):
          
          for iTry in range(1,maxTries+1):
              jobFile = self._getJobFileName(jobStoreID)
              if os.path.exists(jobFile):
                  return True
              if iTry >= maxTries:
                  return False
              elif iTry == 1:
                  logger.warning(("Job file `{}` for job `{}` does not exist (yet). We will try #{} more times with {}s "
                          "intervals.").format(jobFile, jobStoreID, maxTries - iTry, sleepTime))
              time.sleep(sleepTime)
          return False
docs: Spin-wait and block for a file to appear before returning False if it does not.
          
          The total max wait time is maxTries * sleepTime. The current default is
          tuned to match Linux NFS defaults where the client's cache of the directory
          listing on the server is supposed to become coherent within 30 sec.
          Delayes beyond that would probably indicate a pathologically slow file system
          that just should not be used for the jobStore.
          
          The warning will be sent to the log only on the first retry.
          
          In practice, the need for retries happens rarely, but it does happen
          over the course of large workflows with a jobStore on a busy NFS.