Would it be possible to define constants for the mongo operators somewhere in the library? e.g.

const (
  Set = "$set"
  Unset = "$unset"
  CurrentDate = "$currentDate"
  .....
)

We recently started using sonarqube and it rightly so complains about duplicating strings in the code more than x times.

We maintain an internal set of libraries where we could also consider adding these but I would assume more people would benefit from having these into the core library.