:+1: on keeping that part unchanged

```
The returned relation implements the Null Object pattern. It is an object with defined null behavior and always returns an empty array of records without querying the database.

Any subsequent condition chained to the returned relation will continue generating an empty relation and will not fire any query to the database.
```

This seems good enough (the key point is to remove the mention about `NullRelation` since it's private). The null behavior part still seems unnecessarily technical to me, but the attempts to reduce that isn't too fruitful so far, and unfortunately I don't have any better alternatives to suggest.

So I recommend keeping the change minimal here.