code: @Override
    public SpanWeight createWeight(IndexSearcher searcher, boolean needsScores, float boost)
        throws IOException {
      SpanWeight subWeight = query.createWeight(searcher, needsScores, boost);
      if (maximumLeft == 0 && maximumRight == 0) {
        return subWeight;
      } else {
        return new MtasExpandWeight(subWeight, searcher, needsScores, boost);
      }
    }
docs: /*
  (non-Javadoc)
  
  @see
  mtas.search.spans.util.MtasSpanQuery#createWeight(org.apache.lucene.search.
  IndexSearcher, boolean)