KeyError: 'socketio' in socketio_manager

[ChmutovSergey]

I use the example of simply_pyramid_chat for your project. I started a project with pserve pyramid, use view.py from the example. But I received KeyError: 'socketio' in socketio.init.py socketio_manager line 67

def socketio_service(request):
    socketio_manage(request.environ, {'/chat': TestNamespace}, request=request)

    return Response('')

reques.environ has no attribute 'socketio'

reques.environ

<class 'dict'>: {'SERVER_NAME': 'debian', 'HTTP_HOST': '0.0.0.0:6543', 'SCRIPT_NAME': '', 'HTTP_USER_AGENT': 'Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0', 'SERVER_PORT': '6543', 'webob.is_body_seekable': True, 'webob._cache_control': ('', <CacheControl ''>), 'wsgi.errors': <_io.TextIOWrapper name='<stderr>' mode='w' encoding='UTF-8'>, 'SERVER_PROTOCOL': 'HTTP/1.1', 'HTTP_ACCEPT': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', 'REMOTE_PORT': '38674', 'HTTP_ACCEPT_LANGUAGE': 'ru-RU,ru;q=0.8,en-US;q=0.5,en;q=0.3', 'webob._parsed_cookies': ({}, ''), 'wsgi.url_scheme': 'http', 'wsgi.multiprocess': False, 'wsgi.input': <_io.BytesIO object at 0x7ff315d61200>, 'webob._parsed_query_vars': (GET([]), ''), 'wsgi.run_once': False, 'QUERY_STRING': '', 'SERVER_SOFTWARE': 'waitress', 'HTTP_UPGRADE_INSECURE_REQUESTS': '1', 'REMOTE_ADDR': '127.0.0.1', 'wsgi.input_terminated': True, 'CONTENT_LENGTH': '0', 'HTTP_CONNECTION': 'keep-alive', 'wsgi.version': (1, 0), 'PATH_INFO': '/socket.io/chat', 'wsgi.file_wrapper': <class 'waitress.buffers.ReadOnlyFileBasedBuffer'>, 'REMOTE_HOST': '127.0.0.1', 'HTTP_ACCEPT_ENCODING': 'gzip, deflate', 'wsgiorg.routing_args': ((), {}), 'wsgi.multithread': True, 'REQUEST_METHOD': 'GET'}

What could be the problem? Thanks!