How to use the azure-mgmt-notificationhubs.azure.mgmt.notificationhubs.operations.operations.Operations function in azure-mgmt-notificationhubs

def __init__(
            self, credentials, subscription_id, base_url=None):

        self.config = NotificationHubsManagementClientConfiguration(credentials, subscription_id, base_url)
        super(NotificationHubsManagementClient, self).__init__(self.config.credentials, self.config)

        client_models = {k: v for k, v in models.__dict__.items() if isinstance(v, type)}
        self.api_version = '2017-04-01'
        self._serialize = Serializer(client_models)
        self._deserialize = Deserializer(client_models)

        self.operations = Operations(
            self._client, self.config, self._serialize, self._deserialize)
        self.namespaces = NamespacesOperations(
            self._client, self.config, self._serialize, self._deserialize)
        self.notification_hubs = NotificationHubsOperations(
            self._client, self.config, self._serialize, self._deserialize)