getValue is never called by the library when using custom column

the example is erroneous:

https://bossanova.uk/jspreadsheet/v4/examples/column-types

also the interface is missing setValue:

  interface CustomEditor {
    /**
     * Event responsible for closing the editor of a cell with a custom editor.
     * @param cell - Td tag whose editor should close.
     * @param save - If true, the value returned by this event will be the cell's new value. Otherwise, the value returned by this event is ignored.
     */
    closeEditor?: (
      cell: HTMLTableCellElement,
      save: boolean
    ) => CellValue | undefined;

    /**
     * Event called when creating new cells.
     * @param cell - HTML element prepared to be the new cell.
     * @returns HTML element that will be the new cell
     */
    createCell?: (cell: HTMLTableCellElement) => HTMLTableCellElement;

    /**
     * Event responsible for opening the editor of a cell with a custom editor.
     * @param cell - Td tag whose editor should open.
     * @param el - Root HTML element of this jss instance.
     * @param empty - If true, the editor should open with no value.
     * @param e - Event that called this method.
     */
    openEditor?: (
      cell: HTMLTableCellElement,
      el: JspreadsheetInstanceElement,
      empty: boolean | undefined,
      e: TouchEvent | undefined
    ) => void;

    /**
     * Event called before changing the value of a cell.
     *
     * The returned value will be the cell's new value.
     * @param cell - Cell whose value has changed.
     * @param value - New value.
     * @param force - If true, the change is configured to occur even in read-only cells.
     */
    updateCell?: (
      cell: HTMLTableCellElement,
      value: CellValue | undefined,
      force: boolean | undefined
    ) => CellValue | undefined;
  }

Start with the custom column example at https://bossanova.uk/jspreadsheet/v4/examples/column-types and the CustomEditor interface shown in the issue. Trace how custom-column values are read and written, then verify that getValue is invoked as expected and that the interface exposes the required setValue member.