abstract public  void collect(int doc,
    float score)
Called once for every document matching a query, with the document
number and its raw score.

If, for example, an application wished to collect all of the hits for a
query in a BitSet, then it might:
  Searcher searcher = new IndexSearcher(indexReader);
  final BitSet bits = new BitSet(indexReader.maxDoc());
  searcher.search(query, new HitCollector() {
      public void collect(int doc, float score) {
        bits.set(doc);
      }
    });


Note: This is called in an inner search loop.  For good search
performance, implementations of this method should not call
Searcher#doc(int)  or
org.apache.lucene.index.IndexReader#document(int)  on every
document number encountered.  Doing so can slow searches by an order
of magnitude or more.
Note: The score passed to this method is a raw score.
In other words, the score will not necessarily be a float whose value is
between 0 and 1.