Creates a new RetryTransport.
Retry transport configuration.
Sends the request with automatic retry on transient failures. On expired auth tokens, calls RetryTransportOptions.onReauth and retries.
The HTTP request to execute. The caller's reference is not mutated; on reauth, a copy with a refreshed Authorization header is sent.
The HTTP response.
Transport wrapper that adds automatic retry with exponential backoff. Handles transient B2 errors (408, 429, 503), expired auth tokens, and network failures. Delegates to an inner HttpTransport.