How to use the bravado.client.SwaggerClient.from_spec function in bravado

def index(request):
    ctx = RequestContext(request)
    ctx['email'] = request.META.get('HTTP_X_CONSUMER_USERNAME')
    api_key = request.META.get('HTTP_X_CONSUMER_CUSTOM_ID')
    if api_key and ctx['email']:
        http_client.set_api_key(
            os.environ['MPCONTRIBS_API_HOST'], b64decode(api_key),
            param_in='header', param_name='x-api-key'
        )
        client = SwaggerClient.from_spec(
            spec_dict, http_client=http_client,
            config={'validate_responses': False}
        )
        ctx['landing_pages'] = []
        provenances = client.provenances.get_provenances().response().result
        for provenance in provenances:
            explorer = 'mpcontribs_users_{}_explorer_index'.format(provenance.project)
            entry = {'project': provenance.project, 'url': '#'}# TODO reverse(explorer)}
            entry['title'] = provenance.title
            authors = provenance.authors.split(',', 1)
            prov_display = '<span style="font-size: 13px;" class="pull-right">{}'.format(authors[0])
            if len(authors) &gt; 1:
                prov_display += '''<button style="padding: 0px 0px 2px 5px;" title="{}" data-container="body" data-placement="bottom" data-toggle="tooltip" data-html="true" class="btn btn-sm btn-link">et al.'''.format(
                    authors[1].strip().replace(', ', '<br>'))</button></span>

def get_client(
    url: str,
    schema: Optional[Dict[str, Any]] = None,
):
    """
    :param url: server URL
    """
    if not schema:
        return SwaggerClient.from_url(url)

    return SwaggerClient.from_spec(
        schema,
        origin_url=url,
    )

log.error("paasta-api swagger spec %s does not exist", swagger_file)
        return None

    with open(swagger_file) as f:
        spec_dict = json.load(f)
    # replace localhost in swagger.json with actual api server
    spec_dict["host"] = api_server
    spec_dict["schemes"] = [parsed.scheme]

    # sometimes we want the status code
    requests_client = PaastaRequestsClient(
        scheme=parsed.scheme, cluster=cluster, system_paasta_config=system_paasta_config
    )
    if http_res:
        config = {"also_return_response": True}
        c = SwaggerClient.from_spec(
            spec_dict=spec_dict, config=config, http_client=requests_client
        )
    else:
        c = SwaggerClient.from_spec(spec_dict=spec_dict, http_client=requests_client)
    return paasta_tools.api.auth_decorator.AuthClientDecorator(c, cluster_name=cluster)

def connect(self):
        response = requests.get(
            'https://%s:%s/swagger.json' % (self.host, self.port),
            verify=self.verify)
        if response.status_code == requests.status_codes.codes.OK:
            spec = response.json()
            spec['host'] = '%s:%s' % (self.host, self.port)
            http_client = RequestsClient()
            http_client.session.verify = self.verify
            config = {
                'validate_swagger_spec': True
            }
            self.client = SwaggerClient.from_spec(spec,
                                                  http_client=http_client,
                                                  config=config)
        else:
            raise Exception(response)

# 'formats': [],
        }

    host = 'https://www.bitmex.com'
    if test:
        host = 'https://testnet.bitmex.com'
        
    spec_uri = host + '/api/explorer/swagger.json'
    spec_dict = get_swagger_json(spec_uri, exclude_formats=EXCLUDE_SWG_FORMATS)

    if api_key and api_secret:
        request_client = RequestsClient()
        request_client.authenticator = APIKeyAuthenticator(host, api_key, api_secret)
        return SwaggerClient.from_spec(spec_dict, origin_url=spec_uri, http_client=request_client, config=config)
    else:
        return SwaggerClient.from_spec(spec_dict, origin_url=spec_uri, http_client=None, config=config)

def setup_client(
    url: str,
    schema: Optional[Dict[str, Any]] = None,
) -> Optional[str]:
    """
    :returns: error message, if appropriate.
    """
    if get_abstraction().client:
        return None

    try:
        config = {'internally_dereference_refs': True}
        if not schema:
            client = SwaggerClient.from_url(url, config=config)
        else:
            client = SwaggerClient.from_spec(schema, origin_url=url, config=config)
    except requests.exceptions.ConnectionError:
        return 'Unable to connect to server.'
    except (
        simplejson.errors.JSONDecodeError,      # type: ignore
        yaml.YAMLError,
        HTTPError,
    ):
        return (
            'Invalid swagger file. Please check to make sure the '
            'swagger file can be found at: {}.'.format(url)
        )
    except SwaggerValidationError:
        return 'Invalid swagger format.'

    get_abstraction().client = client
    return None

spec_dict = json.load(f)
    # replace localhost in swagger.json with actual api server
    spec_dict["host"] = api_server
    spec_dict["schemes"] = [parsed.scheme]

    # sometimes we want the status code
    requests_client = PaastaRequestsClient(
        scheme=parsed.scheme, cluster=cluster, system_paasta_config=system_paasta_config
    )
    if http_res:
        config = {"also_return_response": True}
        c = SwaggerClient.from_spec(
            spec_dict=spec_dict, config=config, http_client=requests_client
        )
    else:
        c = SwaggerClient.from_spec(spec_dict=spec_dict, http_client=requests_client)
    return paasta_tools.api.auth_decorator.AuthClientDecorator(c, cluster_name=cluster)