> I don't think it's the right solution here, and won't implement it
> without a more persuasive argument in its favour. The additional
> threshold parameter means this can't be used in a
> Pipeline/FeatureUnion, and the threshold can't be evaluated as a
> parameter in a [grid] search. I.e. it's a misfit in your API, as I will
> mention on the ML.

I fully agree