def METHOD_NAME(self):
    manager = EmrSecurityGroupManager(ec2_backend, self.vpc_id)
    assert len(self._default_emr_security_groups()) == 0
    manager.manage_security_groups(None, None, None)
    emr_security_groups = self._default_emr_security_groups()
    assert len(emr_security_groups) == 3
    # Run again.  Group count should still be 3.
    emr_sg_ids_expected = [sg["GroupId"] for sg in emr_security_groups]
    manager.manage_security_groups(None, None, None)
    emr_security_groups = self._default_emr_security_groups()
    assert len(emr_security_groups) == 3
    emr_sg_ids_actual = [sg["GroupId"] for sg in emr_security_groups]
    assert emr_sg_ids_actual == emr_sg_ids_expected