Overrides Constraint::ERROR_NAMES
protected const ERROR_NAMES = [ self::TOO_FEW_ERROR => 'TOO_FEW_ERROR', self::TOO_MANY_ERROR => 'TOO_MANY_ERROR', self::NOT_EQUAL_COUNT_ERROR => 'NOT_EQUAL_COUNT_ERROR', self::NOT_DIVISIBLE_BY_ERROR => 'NOT_DIVISIBLE_BY_ERROR', ];