public function absorbRowContent(TableRow $targetRow) : void
    {
        // iterate over each column and combine the content
        foreach ($this->getColumns() as $columnIndex => $column) {
            $targetColumn = $targetRow->getColumn($columnIndex);
            if ($targetColumn === null) {
                throw new InvalidTableStructure(sprintf('Malformed table: lines "%s" and "%s" appear to be in the same row, but don\'t share the same number of columns.', $this->toString(), $targetRow->toString()));
            }

            $column->addContent("\n" . $targetColumn->getContent());
        }
    }