Call the service's API action to retrieve limit/quota information, and
        update AwsLimit objects in ``self.limits`` with this information.

def _update_limits_from_api(self):
        """
        Call the service's API action to retrieve limit/quota information, and
        update AwsLimit objects in ``self.limits`` with this information.
        """
        logger.debug('Setting DirectoryService limits from API')
        self.connect()
        resp = self.conn.get_directory_limits()
        directory_limits = resp['DirectoryLimits']
        self.limits['CloudOnlyDirectories']._set_api_limit(
            directory_limits['CloudOnlyDirectoriesLimit']
        )
        self.limits['CloudOnlyMicrosoftAD']._set_api_limit(
            directory_limits['CloudOnlyMicrosoftADLimit']
        )
        self.limits['ConnectedDirectories']._set_api_limit(
            directory_limits['ConnectedDirectoriesLimit']
        )