code: @Override
    public MtasSpanWeight createWeight(IndexSearcher searcher,
        boolean needsScores, float boost) throws IOException {
      SpanWeight spanWeight = ((SpanQuery) searcher.rewrite(clause))
          .createWeight(searcher, needsScores, boost);
      return new SpanTermWeight(spanWeight, searcher, boost);
    }
docs: /*
  (non-Javadoc)
  
  @see
  org.apache.lucene.search.spans.SpanQuery#createWeight(org.apache.lucene.
  search.IndexSearcher, boolean)