docs: public boolean preProcess(ConfigEntry configEntry) {
          boolean valid = true;
          // there is no override, use the default processorData
          if (configEntry.processorData == null)
              configEntry.processorData = new Object[BASE_SLOTS];
          //persistToDisk                                            
          Property p = (Property) configEntry.properties.get(PROPERTY_PERSIST_TO_DISK);
          String val = p != null ? (String) p.value : null;
          if (val != null) {
              val = val.trim();
              configEntry.processorData[SLOT_PERSIST_TO_DISK] = new Boolean(val);
          }
  
          //do-not-cache                                            
          p = (Property) configEntry.properties.get(PROPERTY_DO_NOT_CACHE);
          val = p != null ? (String) p.value : null;
          if (val != null) {
              configEntry.processorData[SLOT_DO_NOT_CACHE] = new Boolean(val);
          }
  
          for (int i = 0; i < configEntry.cacheIds.length; i++)
              valid &= preProcess(configEntry.cacheIds[i]);
          return valid;
      }