code: @Override
    public Envelope convertResponse(HttpResponse response) throws ResponseConversionException {
      if (!(response instanceof HttpContent)) {
        throw new ResponseConversionException(response);
      }
  
      HttpContent content = (HttpContent) response;
      try {
        return Envelope.PARSER.parseFrom(ByteBufUtil.getBytes(content.content()));
      } catch (InvalidProtocolBufferException ipbe) {
        throw new ResponseConversionException(
            String.format("HTTP status: %d, Content: %s", response.getStatus().code(),
                content.content().toString(Charsets.UTF_8)), ipbe);
      }
    }
docs: {@inheritDoc}