private function checkRowConsistency($row)
    {
        if ( $this->strict === false ) {
            return;
        }

        $current = count($row);

        if ( $this->rowConsistency === null ) {
            $this->rowConsistency = $current;
        }

        if ( $current !== $this->rowConsistency ) {
            throw new StrictViolationException();
        }

        $this->rowConsistency = $current;
    }