GET /as/authorization.oauth2?response_type=code
     &client_id=s6BhdRkqt3
     &state=tNwzQ87pC6llebpmac_IDeeq-mCR2wLDYljHUZUAWuI
     &redirect_uri=https%3A%2F%2Fclient.example.org%2Fcb
     &scope=calendar%20contacts
     &resource=https%3A%2F%2Fcal.example.com%2F
     &resource=https%3A%2F%2Fcontacts.example.com%2F HTTP/1.1
  Host: authorization-server.example.com