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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_property_orders(query_proto, *orders):
 """Add ordering constraint for the given datastore.Query proto message. Args: query_proto: datastore.Query proto message. orders: list of propertype name string, default to ascending order and set descending if prefixed by '-'. Usage: """

  for order in orders:
    proto = query_proto.order.add()
    if order[0] == '-':
      order = order[1:]
      proto.direction = query_pb2.PropertyOrder.DESCENDING
    else:
      proto.direction = query_pb2.PropertyOrder.ASCENDING
    proto.property.name = order