"fields" isn't fully supported

[MichaelXavier]

I was just going to solve this but I ended up not needing this, so I figured I'd write it up here as a known issue and discuss the solution.

We support specifying "fields" in the search. When you do that, the response will have a fields attribute with a map from field name to value. Combining the docs and my experimentation, the fields you specify must be "leaves". If we want to be really precise with the types, the type would be something like HashMap Text ValueWithNoObjectConstructor