def _prime_executor(self):
    futures = [self.executor.submit(time.sleep, 0.1) for _ in range(self.worker_count)]
    for f in futures:
        f.result()
def _prime_executor(self):
    futures = [self.executor.submit(time.sleep, 0.1) for _ in range(self.worker_count)]
    for f in futures:
        f.result()