static <T> StreamMessage<T> of(T obj1, T obj2) {
        requireNonNull(obj1, "obj1");
        requireNonNull(obj2, "obj2");
        return new TwoElementFixedStreamMessage<>(obj1, obj2);
    }
Creates a new {@link StreamMessage} that will publish the two {@code obj1} and {@code obj2}.
core/src/main/java/com/linecorp/armeria/common/stream/StreamMessage.java