How to use the wechatpy.utils.json function in wechatpy

def wechat_api_mock(url, request):
    path = url.path[1:].replace('/', '_')
    res_file = os.path.join(_FIXTURE_PATH, '%s.json' % path)
    content = {
        'errcode': 99999,
        'errmsg': 'can not find fixture: %s' % res_file
    }
    headers = {
        'Content-Type': 'application/json'
    }
    try:
        with open(res_file) as f:
            content = json.loads(f.read())
    except (IOError, ValueError):
        content['errmsg'] = 'Fixture %s json decode error' % res_file
    return response(200, content, headers, request=request)

def wechat_api_mock(url, request):
    path = url.path.replace('/cgi-bin/component/', '').replace('/', '_')
    res_file = os.path.join(_FIXTURE_PATH, '%s.json' % path)
    content = {
        'errcode': 99999,
        'errmsg': 'can not find fixture %s' % res_file,
    }
    headers = {
        'Content-Type': 'application/json'
    }
    try:
        with open(res_file, 'rb') as f:
            content = json.loads(f.read().decode('utf-8'))
    except (IOError, ValueError):
        pass
    return response(200, content, headers, request=request)

def next_openid_mock(url, request):
            """伪造第二页的请求"""
            data = json.loads(request.body.decode())
            if not data.get('next_openid'):
                return wechat_api_mock(url, request)

            # 根据拿到的第二页请求响应 是没有data和next_openid的
            content = {
                "count": 0
            }
            headers = {
                'Content-Type': 'application/json'
            }
            return response(200, content, headers, request=request)

def wechat_api_mock(url, request):
    path = url.path.replace('/cgi-bin/', '').replace('/', '_')
    res_file = os.path.join(_FIXTURE_PATH, '%s.json' % path)
    content = {
        'errcode': 99999,
        'errmsg': 'can not find fixture %s' % res_file,
    }
    headers = {
        'Content-Type': 'application/json'
    }
    try:
        with open(res_file, 'rb') as f:
            content = json.loads(f.read().decode('utf-8'))
    except (IOError, ValueError) as e:
        content['errmsg'] = 'Loads fixture {0} failed, error: {1}'.format(
            res_file,
            e
        )
    return response(200, content, headers, request=request)

def get(self, key, default=None):
        key = self.key_name(key)
        value = self.mc.get(key)
        if value is None:
            return default
        return json.loads(to_text(value))

res = self._http.request(
            method=method,
            url=url,
            **kwargs
        )
        try:
            res.raise_for_status()
        except requests.RequestException as reqe:
            raise WeChatOAuthException(
                errcode=None,
                errmsg=None,
                client=self,
                request=reqe.request,
                response=reqe.response
            )
        result = json.loads(res.content.decode('utf-8', 'ignore'), strict=False)

        if 'errcode' in result and result['errcode'] != 0:
            errcode = result['errcode']
            errmsg = result['errmsg']
            raise WeChatOAuthException(
                errcode,
                errmsg,
                client=self,
                request=res.request,
                response=res
            )

        return result

def _request(self, method, url_or_endpoint, **kwargs):
        if not url_or_endpoint.startswith(('http://', 'https://')):
            url = '{base}{endpoint}'.format(
                base=self.API_BASE_URL,
                endpoint=url_or_endpoint
            )
        else:
            url = url_or_endpoint

        if isinstance(kwargs.get('data', ''), dict):
            body = json.dumps(kwargs['data'], ensure_ascii=False)
            body = body.encode('utf-8')
            kwargs['data'] = body

        res = self._http.request(
            method=method,
            url=url,
            **kwargs
        )
        try:
            res.raise_for_status()
        except requests.RequestException as reqe:
            raise WeChatOAuthException(
                errcode=None,
                errmsg=None,
                client=self,
                request=reqe.request,

if not url_or_endpoint.startswith(('http://', 'https://')):
            api_base_url = kwargs.pop('api_base_url', self.API_BASE_URL)
            url = '{base}{endpoint}'.format(
                base=api_base_url,
                endpoint=url_or_endpoint
            )
        else:
            url = url_or_endpoint

        if 'params' not in kwargs:
            kwargs['params'] = {}
        if isinstance(kwargs['params'], dict) and \
                'access_token' not in kwargs['params']:
            kwargs['params']['access_token'] = self.access_token
        if isinstance(kwargs.get('data', ''), dict):
            body = json.dumps(kwargs['data'], ensure_ascii=False)
            body = body.encode('utf-8')
            kwargs['data'] = body

        kwargs['timeout'] = kwargs.get('timeout', self.timeout)
        result_processor = kwargs.pop('result_processor', None)
        res = self._http.request(
            method=method,
            url=url,
            **kwargs
        )
        try:
            res.raise_for_status()
        except requests.RequestException as reqe:
            raise WeChatClientException(
                errcode=None,
                errmsg=None,

:param title: 视频素材标题，仅上传视频素材时需要
        :param introduction: 视频素材简介，仅上传视频素材时需要
        :return: 返回的 JSON 数据包
        """
        params = {
            'access_token': self.access_token,
            'type': media_type
        }
        if media_type == 'video':
            assert title, 'Video title must be set'
            assert introduction, 'Video introduction must be set'
            description = {
                'title': title,
                'introduction': introduction
            }
            params['description'] = json.dumps(description)
        return self._post(
            'material/add_material',
            params=params,
            files={
                'media': media_file
            }

def set(self, key, value, ttl=None):
        if value is None:
            return
        with open('%s-%s'%(self.file_dir, key), 'w') as f:
            value = json.dumps({'val': value, 'expires_at': ttl and int(time.time()) + ttl or 0})
            f.write(value)