How to use the azure-mgmt-commerce.azure.mgmt.commerce.version.VERSION function in azure-mgmt-commerce

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

        if credentials is None:
            raise ValueError("Parameter 'credentials' must not be None.")
        if subscription_id is None:
            raise ValueError("Parameter 'subscription_id' must not be None.")
        if not base_url:
            base_url = 'https://management.azure.com'

        super(UsageManagementClientConfiguration, self).__init__(base_url)

        self.add_user_agent('azure-mgmt-commerce/{}'.format(VERSION))
        self.add_user_agent('Azure-SDK-For-Python')

        self.credentials = credentials
        self.subscription_id = subscription_id