AttributeError: '_Server' object has no attribute 'wait_for_termination'

grpc 的server.wait_for_termination如果报错，可以按照如下代码代替，python版本的：

import time

def serve():
    log = QscLog()
    server = grpc.server(futures.ThreadPoolExecutor(max_workers=20))
    add_ProjectAmountServicer_to_server(ProjectAmount(), server)
    server.add_insecure_port(':8001')
    server.start()
    log.info("server start...")
    while 1:
        time.sleep(10)