def _sign_of(money):
    """Determines the amount sign of a money instance

    Args:
      money (:class:`endpoints_management.gen.servicecontrol_v1_messages.Money`): the
        instance to test

    Return:
      int: 1, 0 or -1

    """
    units = money.units
    nanos = money.nanos
    if units:
        if units > 0:
            return 1
        elif units < 0:
            return -1
    if nanos:
        if nanos > 0:
            return 1
        elif nanos < 0:
            return -1
    return 0