More Like This Query

I’d like to use “More Like This” query.

I found this information.

I add “mlt.field=content_ja” to search.jsp.
But, It doesn’t work.

Is this setting wrong?
Could you please give any example or advise?

Not supported from 10.

OK. I’ll try to check source code…
Are you planning to support in the future?

No plan. Any contributions are welcome.