in src/core.ts [605:626]
private shouldRetry(response: Response): boolean {
// Note this is not a standard header.
const shouldRetryHeader = response.headers.get('x-should-retry');
// If the server explicitly says whether or not to retry, obey.
if (shouldRetryHeader === 'true') return true;
if (shouldRetryHeader === 'false') return false;
// Retry on request timeouts.
if (response.status === 408) return true;
// Retry on lock timeouts.
if (response.status === 409) return true;
// Retry on rate limits.
if (response.status === 429) return true;
// Retry internal errors.
if (response.status >= 500) return true;
return false;
}