docs: @Override
      protected Query parseQuery( TokenStream tokens,
                                  TypeSystem typeSystem ) {
          Query query = super.parseQuery(tokens, typeSystem);
          // See if we have to rewrite the JCR-SQL-style join ...
          if (query.source() instanceof JoinableSources) {
              JoinableSources joinableSources = (JoinableSources)query.source();
              // Rewrite the joins ...
              Source newSource = rewrite(joinableSources);
              query = new Query(newSource, query.constraint(), query.orderings(), query.columns(), query.getLimits(),
                                query.isDistinct());
          }
          return query;
      }