How to use the azure-mgmt-commerce.azure.mgmt.commerce.models.__dict__ function in azure-mgmt-commerce

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

        self.config = UsageManagementClientConfiguration(credentials, subscription_id, base_url)
        self._client = ServiceClient(self.config.credentials, self.config)

        client_models = {k: v for k, v in models.__dict__.items() if isinstance(v, type)}
        self.api_version = '2015-06-01-preview'
        self._serialize = Serializer(client_models)
        self._deserialize = Deserializer(client_models)

        self.usage_aggregates = UsageAggregatesOperations(
            self._client, self.config, self._serialize, self._deserialize)
        self.rate_card = RateCardOperations(
            self._client, self.config, self._serialize, self._deserialize)