docs: @SuppressWarnings("unused")
      final void handleStatusCode(ByteBuffer buffer, ResponseParseState state, HttpResponseBuilder builder) {
          StringBuilder stringBuilder = state.stringBuilder;
          while (buffer.hasRemaining()) {
              final char next = (char) buffer.get();
              if (next == ' ' || next == '\t') {
                  builder.setStatusCode(Integer.parseInt(stringBuilder.toString()));
                  state.state = ResponseParseState.REASON_PHRASE;
                  state.stringBuilder.setLength(0);
                  state.parseState = 0;
                  state.pos = 0;
                  state.nextHeader = null;
                  return;
              } else {
                  stringBuilder.append(next);
              }
          }
      }