docs: boolean forceDefrag() {
  
          long megas = properties.getIntegerProperty(
              HsqlDatabaseProperties.hsqldb_defrag_limit, 200);
          long defraglimit = megas * 1024L * 1024;
          long lostSize    = cache.freeBlocks.getLostBlocksSize();
  
          return lostSize > defraglimit;
      }