code: protected synchronized void indexSearcherClose(IndexSearcher searcher) {
  
          // in case there is an index searcher available close it
          if ((searcher != null) && (searcher.getIndexReader() != null)) {
              try {
                  searcher.getIndexReader().close();
              } catch (Exception e) {
                  LOG.error(Messages.get().getBundle().key(Messages.ERR_INDEX_SEARCHER_CLOSE_1, getName()), e);
              }
          }
      }
docs: Closes the given Lucene index searcher.<p>
  
  @param searcher the searcher to close