It won't work to `belongs_to`, `has_and_belongs_to_many` or `has_many` automatically.
If user creates:
```erb
<%= f.filter_input :parents, as: : check_boxes  # collection %>
```
It will try to find 
```ruby
object.klass.uniq.pluck(:parents) # and will fail
```

If you want you can add `Collection` and `BelongsTo` classes for check_boxes by analogy with `Select`