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