models shared True
# upper_alike in-process sync, in-process async
straße X-A
  > GET /a
  straße()
  < 200 application/json
  = AGetResponse200XAHeader(root=7)
strasse X-B
  > GET /b
  strasse()
  < 200 application/json
  = BGetResponse200XBHeader(root='text')
