docs: protected void cleanAndReindex( boolean async ) {
          final IndexWriter writer = getIndexWriter();
          scan(async, getIndexWriter(), new Callable<Void>() {
              @SuppressWarnings( "synthetic-access" )
              @Override
              public Void call() throws Exception {
                  writer.clearAllIndexes();
                  reindexContent(true, writer);
                  return null;
              }
          });
      }