code: def _PrepareAttributeContainer(self, attribute_container):
      
      attribute_values_hash = hash(attribute_container.GetAttributeValuesString())
      identifier = identifiers.FakeIdentifier(attribute_values_hash)
      attribute_container.SetIdentifier(identifier)
  
      # Make sure the fake storage preserves the state of the attribute container.
      return copy.deepcopy(attribute_container)
docs: Prepares an attribute container for storage.
  
      Args:
        attribute_container (AttributeContainer): attribute container.
  
      Returns:
        AttributeContainer: copy of the attribute container to store in
            the fake storage.