docs: @Override
    public final List<String> retrieveList() throws Exception {
      List<String> result = new ArrayList<String>();
      File dbDir = new File(this.databaseDir);
      if (dbDir.exists() && dbDir.isDirectory()) {
        String[] files = dbDir.list();
        if (files != null) {
          for (String flNm : files) {
            if (flNm.endsWith(".sqlite")) {
              result.add(flNm.replace(".sqlite", ""));
            }
          }
        }
      } else {
        throw new ExceptionWithCode(ExceptionWithCode.CONFIGURATION_MISTAKE,
          "DB directory not found: " + this.databaseDir);
      }
      return result;
    }