Function goes_in_parts 

pub fn goes_in_parts(storage: &(impl Storage + ?Sized), size: u64) -> bool

Whether an object of size bytes goes up in parts rather than in one request: past the provider’s single-request limit or BUFFERED_REQUEST_LIMIT, whichever is less (§20.6). The 64-KiB encryption chunk plays no part. Every upload routes by this alone: a create of complete bytes, and a caller sending a repeatable source, which reads it whole only for one request and otherwise records a session.