code: def hash(self):
          '''
          :rtype: int
          :return: hash of the field
          '''
          hashed = super(Calculated, self).hash()
          return khash(hashed, self._field_namef hash(self):
          '''
          :rtype: int
          :return: hash of the field
          '''
          hashed = super(Calculated, self).hash()
          return khash(hashed, self._field_name)
docs: :rtype: int
          :return: hash of the field