code: public static <T, V> FactorFilter<T, V> create(final String factorName,
        final Filter<T, V> filter) {
  
      if (null == factorName || factorName.length() == 0 || null == filter) {
        logger.error(
            "failed to create instance of FactorFilter, at least one of the input paramters are invalid");
        return null;
      }
  
      return new FactorFilter<>(factorName, filter);
    }
docs: static function to generate an instance of the class. refer to the constructor for the param
  definitions.