code: public static HttpResponseStatus parseStatus(CharSequence status) throws Http2Exception {
          HttpResponseStatus result;
          try {
              result = parseLine(status);
              if (result == HttpResponseStatus.SWITCHING_PROTOCOLS) {
                  throw connectionError(PROTOCOL_ERROR, "Invalid HTTP/2 status code '%d'", result.code());
              }
          } catch (Http2Exception e) {
              throw e;
          } catch (Throwable t) {
              throw connectionError(PROTOCOL_ERROR, t,
                              "Unrecognized HTTP status code '%s' encountered in translation to HTTP/1.x", status);
          }
          return result;
      }
docs: Apply HTTP/2 rules while translating status code to {@link HttpResponseStatus}
  
  @param status The status from an HTTP/2 frame
  @return The HTTP/1.x status
  @throws Http2Exception If there is a problem translating from HTTP/2 to HTTP/1.x