SelectionCommandHandler with option `multi: true`, it does not work correctly


I am using SelectionCommandHandler.
In case of option multi: false, it work correctly.
But, in case of option multi: true, it dose not work correctly. The argument to SelectionCommandHandler.execute() is always an array of length 1, even if there are multiple items in SelectionService.selection.

SelectionCommandHandler.getSelection() is implemented as follows:

protected getSelection(...args: any[]): S | S[] | undefined {
    const givenSelection = args.length && this.toSelection(args[0]);
    if (givenSelection) {
        return this.isMulti() ? [givenSelection] : givenSelection;
    const globalSelection = this.getSingleSelection(this.selectionService.selection);
    if (this.isMulti()) {
        return this.getMultiSelection(globalSelection);
    return this.getSingleSelection(globalSelection);

Isn’t Line 6: const globalSelection = this.getSingleSelection(this.selectionService.selection) a mistake and correct implementation is const globalSelection = this.selectionService.selection?