class Pet(db.Model):
  name = db.StringProperty(required=True)
  type = db.StringProperty(required=True, choices=set(["cat", "dog", "bird"]))
  birthdate = db.DateProperty()
  weight_in_pounds = db.IntegerProperty()
  spayed_or_neutered = db.BooleanProperty()
  owner = db.UserProperty(required=True)