docs: protected void transportTrailersReceived(Metadata trailers) {
      Preconditions.checkNotNull(trailers, "trailers");
      if (transportError == null && !headersReceived) {
        transportError = validateInitialMetadata(trailers);
        if (transportError != null) {
          transportErrorMetadata = trailers;
        }
      }
      if (transportError != null) {
        transportError = transportError.augmentDescription("trailers: " + trailers);
        http2ProcessingFailed(transportError, false, transportErrorMetadata);
      } else {
        Status status = statusFromTrailers(trailers);
        stripTransportDetails(trailers);
        inboundTrailersReceived(trailers, status);
      }
    }