unauthorized = 401, //!< unauthorized
forbidden = 403, //!< forbidden
not_found = 404, //!< not_found
+ length_required = 411, //!< length_required
+ payload_too_large = 413, //!< payload_too_large
internal_server_error = 500, //!< internal_server_error
not_implemented = 501, //!< not_implemented
bad_gateway = 502, //!< bad_gateway