twoPhaseIterator

Optional method: Return a TwoPhaseIterator view of this Scorer. A return value of null indicates that two-phase iteration is not supported.

Note that the returned TwoPhaseIterator's approximation must advance synchronously with the .iterator: advancing the approximation must advance the iterator and vice-versa.

Implementing this method is typically useful on Scorers that have a high per-document overhead in order to confirm matches.

The default implementation returns null.