def setUpClass(cls):
        super(VolumeQuotasNegativeTestJSON, cls).setUpClass()
        demo_user = cls.isolated_creds.get_primary_creds()
        cls.demo_tenant_id = demo_user.tenant_id
        cls.shared_quota_set = {'gigabytes': 3, 'volumes': 1, 'snapshots': 1}

        # NOTE(gfidente): no need to restore original quota set
        # after the tests as they only work with tenant isolation.
        resp, quota_set = cls.quotas_client.update_quota_set(
            cls.demo_tenant_id,
            **cls.shared_quota_set)

        # NOTE(gfidente): no need to delete in tearDown as
        # they are created using utility wrapper methods.
        cls.volume = cls.create_volume()
        cls.snapshot = cls.create_snapshot(cls.volume['id'])