# 1. GET: URL, method and the decoded record
findById(1) -> Post[id=1, userId=1, title=Test Title, body=Test body]

# 2. POST: the request body the interface sent
create(...) -> id 101 (request matched: path, method, Content-Type, JSON body)

# 3. a ProblemDetail 404 goes through the real status handler
findById(9) -> UpstreamNotFoundException (handler decoded the body: 'No post with id 9')

# 4. a 500 with no body: the handler falls back instead of crashing
findAll() -> UpstreamUnavailableException: Upstream unavailable (500): (no problem+json body)

# 5. what MockRestServiceServer cannot tell you
timeouts, connection resets, TLS and real serialisation quirks never happen here; see 03 and 05 for the real server.
