src/vs/workbench/contrib/markers/browser/markersView.ts/MarkersView/getFocusedSelectedElements
class MarkersView:	public getFocusedSelectedElements(): MarkerElement[] | null {
		const focus = this.getFocusElement();
		if (!focus) {
			return null;
		}
		const selection = this.widget.getSelection();
		if (selection.includes(focus)) {
			const result: MarkerElement[] = [];
			for (const selected of selection) {
				if (selected) {
					result.push(selected);
				}
			}
			return result;
		} else {
			return [focus];
		}
	}