In which cases UploadFile.size can be None?

[kuyugama]

I walked through formparsers code and found out. That all UploadFile instances are created with initial value of the size field set to 0. So, I think, annotation of the attribute should be set to just int, not int | None.

Reference for the UploadFile.size parameter.
https://github.com/encode/starlette/blob/fa5355442753f794965ae1af0f87f9fec1b9a3de/starlette/datastructures.py#L422

Reference for the code that creates UploadFile instance in formparsers.
https://github.com/encode/starlette/blob/fa5355442753f794965ae1af0f87f9fec1b9a3de/starlette/formparsers.py#L211-L216

[kuyugama]

I didn't create issue for this, because I think this is intentional. But even if this is - I don't get the purpose