+val last_errno : t -> int
+(** [last_errno g] returns the last errno that happened on the handle [g]
+ (or [0] if there was no errno). Note that the returned integer is the
+ raw errno number, and it is {i not} related to the {!Unix.error} type.
+
+ [last_errno] can be overwritten by subsequent operations on a handle,
+ so if you want to capture the errno correctly, you must call this
+ in the {!Error} exception handler, before any other operation on [g]. *)
+
+val user_cancel : t -> unit
+(** Cancel current transfer. This is safe to call from OCaml signal
+ handlers and threads. *)
+