Move the NLP to Query Engine priority mapping function to the controller class.
Make the show query filter value a variant, depending on the type of the property we are filter on.
Support isCompleted.
The comparator value is not optional.
The value for the predicate is not optional.
Fix broken tests.
Test for predicate filtering.
Improve code coverage by filtering all possible permutations, and also using STL builtins.
Instead of copypasting all the test cases, generate all the test cases for each type and run through all the comparators.