Extract Options from potentially null JSON values using for expression

Question

I have a JSON document where some values can be null. Using for expressions in json4s, how I can yield None, instead of nothing?

The following will fail to yield whe

Answer 1

What about this

 for {
      JObject(thing) <- res1      
      x = thing.find(_._1 == "PlanEstimate").flatMap(_._2.toOption.map(_.values))
     } yield x