def get_qos_policy_group_name_from_info(qos_policy_group_info):
    """Return the name of a QOS policy group given qos policy group info."""
    if qos_policy_group_info is None:
        return None
    legacy = qos_policy_group_info.get('legacy')
    if legacy is not None:
        return legacy['policy_name']
    spec = qos_policy_group_info.get('spec')
    if spec is not None:
        return spec['policy_name']
    return None