import uuid


def format_volume_id(volume_id):
    """Verifies volume_id and returns it as a str

    Args:
        volume_id: either a str (in which case it's only validated) or bytes object
    """
    try:
        if type(volume_id) is bytes:
            return str(uuid.UUID(bytes=volume_id))
        elif type(volume_id) is str:
            return str(uuid.UUID(hex=volume_id))
    except ValueError:
        pass
    return None