PyTest Tornado：“SimpleAsyncHTTPClient”不可迭代

Question

尝试在 PyTest、Tornado 下制作用于长轮询的测试代码。我的测试代码在下面。conftest.pyfrom tornado.httpclient import  [e-mail] def tornado_server():    print("\ntornado_server()")@pytest.fixtureasync def http_client(tornado_server):    client = AsyncHTTPClient()    return [e-mail]_fixture(scope='session')def event_loop(request):    loop = asyncio.get_event_loop_policy().new_event_loop()    yield loop    loop.close()test_my.pyfrom tornado.httpclient import HTTPRequest, HTTPErrordef test_http_client(event_loop):    url = 'http://httpbin.org/get'    resp = event_loop.run_until_complete(http_client(url))    assert b'HTTP/1.1 200 OK' in resp我希望这个结果以成功结束。但它失败了。def test_http_client(event_loop):    url = 'http://httpbin.org/get'    resp = event_loop.run_until_complete(http_client(url))   assert b'HTTP/1.1 200 OK' in resp E       TypeError: argument of type 'SimpleAsyncHTTPClient' is not iterable我做错了什么？