@UnstableApi
    default <U> StreamMessage<U> decode(StreamDecoder<T, U> decoder) {
        requireNonNull(decoder, "decoder");
        return decode(decoder, ByteBufAllocator.DEFAULT);
    }
Creates a decoded {@link StreamMessage} which is decoded from a stream of {@code T} type objects using
the specified {@link StreamDecoder}.
core/src/main/java/com/linecorp/armeria/common/stream/StreamMessage.java