cell(columnNameOrNumber) {
        let columnNumber = columnNameOrNumber;
        if (typeof columnNameOrNumber === 'string') {
            columnNumber = addressConverter.columnNameToNumber(columnNameOrNumber);
        }

        if (columnNumber < 1) throw new RangeError(`Invalid column number ${columnNumber}. Remember that spreadsheets use 1-based indexing.`);

        // Return an existing cell.
        if (this._cells[columnNumber]) return this._cells[columnNumber];

        // No cell exists for this.
        // Check if there is an existing row/column style for the new cell.
        let styleId;
        const rowStyleId = this._node.attributes.s;
        const columnStyleId = this.sheet().existingColumnStyleId(columnNumber);

        // Row style takes priority. If a cell has both row and column styles it should have created a cell entry with a cell-specific style.
        if (!_.isNil(rowStyleId)) styleId = rowStyleId;
        else if (!_.isNil(columnStyleId)) styleId = columnStyleId;

        // Create the new cell.
        const cell = new Cell(this, columnNumber, styleId);
        this._cells[columnNumber] = cell;
        return cell;
    }
Get a cell in the row.
@param {string|number} columnNameOrNumber - The name or number of the column.
@returns {Cell} The cell.