advanceShallow

Advance to the block of documents that contains target in order to get scoring information about this block. This method is implicitly called by and DocIdSetIterator.nextDoc on the returned doc ID. Calling this method doesn't modify the current DocIdSetIterator.docID. It returns a number that is greater than or equal to all documents contained in the current block, but less than any doc IDS of the next block. target must be >= .docID as well as all targets that have been passed to .advanceShallow so far.