The usable answers a Decision step already gave, read from its own output: the answers a retry
keeps.
A usable answer is final. The graph acts on it as soon as the step completes: a fork's losing
branch is Skipped, and nothing puts it back. So a retry asks only the questions the step is
holding. Asking a usable one again could flip a fork whose other branch is already gone, and leave
neither branch to run.
Empty for a step with no answers of its own: a first run has no output yet, and a failed step's
output is cleared when it is retried (PrepareTaskForRetry).
The usable answers a Decision step already gave, read from its own output: the answers a retry keeps.
A usable answer is final. The graph acts on it as soon as the step completes: a fork's losing branch is Skipped, and nothing puts it back. So a retry asks only the questions the step is holding. Asking a usable one again could flip a fork whose other branch is already gone, and leave neither branch to run.
Empty for a step with no answers of its own: a first run has no output yet, and a failed step's output is cleared when it is retried (
PrepareTaskForRetry).