I've seen just two APIs that returned non-nil/non-default T (representing the partially completed work) with a non-nil error, and those were a constant source o

I've seen just two APIs that returned non-nil/non-default T (representing the partially completed work) with a non-nil error, and those were a constant source of bugs and errors. I've changed those to always return dummy empty T, and even though the retries now hurt performance more (they could not re-use partial completed result), it was a much more straight-forward code.