UserDefined         map[string]string   // only set in case of POST/PUT operations
	ObjectAttributes    map[string]struct{} // Attribute tags defined by the users for the GetObjectAttributes request
	MaxParts            int                 // used in GetObjectAttributes. Signals how many parts we should return

* New Pydantic models use an improved and simplified attribute `model_config` that takes a simple dict instead of an internal class `Config` for their configuration.
    * You can read more about it in the docs for [Declare Request Example Data](https://fastapi.tiangolo.com/tutorial/schema-extra-example/).