docs: private static void writeProperties(Properties props, String keyPrefix, Map<String, Boolean> filters) {
          int counter = 0;
          Set<Entry<String, Boolean>> entrySet = filters.entrySet();
          for (Entry<String, Boolean> entry : entrySet) {
              props.setProperty(keyPrefix + counter, entry.getKey() + BOOL_SEPARATOR + entry.getValue());
              counter++;
          }
          // remove obsolete keys from the properties file
          boolean keyFound = true;
          while (keyFound) {
              String key = keyPrefix + counter;
              String property = props.getProperty(key);
              if (property == null) {
                  keyFound = false;
              } else {
                  props.remove(key);
              }
          }
      }