Parse a Retry-After header value into milliseconds.
Both sanctioned forms are accepted (bare delta-seconds and an HTTP-date), and
anything that does not resolve to a positive finite delay returns undefined
rather than a guess. A provider's hint is provider-supplied input arriving at
a durable boundary, so it is validated here and again by LlmError.
Parameters
value: string|null|undefined
raw header value, or null when the header was absent.
now: number = ...
injectable clock for the HTTP-date form, so the parse is testable.
Parse a
Retry-Afterheader value into milliseconds.Both sanctioned forms are accepted (bare delta-seconds and an HTTP-date), and anything that does not resolve to a positive finite delay returns undefined rather than a guess. A provider's hint is provider-supplied input arriving at a durable boundary, so it is validated here and again by LlmError.