Retrieve all memberships associated with an organization,
        ordered by expiration date.

def get_memberships_for_org(self, account_num, verbose=False):
        """
        Retrieve all memberships associated with an organization,
        ordered by expiration date.
        """
        if not self.client.session_id:
            self.client.request_session()

        query = "SELECT Objects() FROM Membership " \
                "WHERE Owner = '%s' ORDER BY ExpirationDate" % account_num

        membership_list = self.get_long_query(query, verbose=verbose)
        return membership_list or []