@Override
    public void processTrailers(HttpHeaders headers, StreamDecoderOutput<DeframedMessage> out) {
        final String grpcStatus = headers.get(GrpcHeaderNames.GRPC_STATUS);
        if (grpcStatus != null) {
            assert deframedStreamMessage != null;
            trailersReceived = true;
            GrpcStatus.reportStatusLater(headers, deframedStreamMessage, transportStatusListener);
        }
    }
Sets the deframed {@link StreamMessage}.
Note that the {@code deframedStreamMessage} should be set before processing the first {@link HttpObject}.
grpc/src/main/java/com/linecorp/armeria/internal/common/grpc/HttpStreamDeframer.java