How to use the @blueprintjs/table/src.Utils.toBase26Alpha function in @blueprintjs/table

const getCellClipboardData = (row: number, col: number) => {
        return Utils.toBase26Alpha(col) + (row + 1);
    };

cellRenderer(rowIndex: number, columnIndex: number) {
                return {Utils.toBase26Alpha(columnIndex) + (rowIndex + 1)};
            },
        },

columnHeaderCellRenderer: (columnIndex: number) => {
                const alpha = Utils.toBase26Alpha(columnIndex);
                return (
                    
                        <h4>Header {alpha}</h4>
                        <p>Whatever interactive header content goes here lorem ipsum.</p>
                    
                );
            },
        },

Utils.times(nextState.numCols, columnIndex => {
            this.store.setColumnName(columnIndex, `Column ${Utils.toBase26Alpha(columnIndex)}`);
            Utils.times(nextState.numRows, rowIndex => {
                this.store.set(rowIndex, columnIndex, generator(rowIndex, columnIndex));
            });
        });
    };

columnHeaderCellRenderer: (columnIndex: number) => {
                return ;
            },
        },