src/vs/workbench/contrib/markers/browser/markersTreeViewer.ts/MarkerWidget/_getClickModifierKey
class MarkerWidget:	private _getClickModifierKey(): ModifierKey {
		const value = this._configurationService.getValue<'ctrlCmd' | 'alt'>('editor.multiCursorModifier');
		if (value === 'ctrlCmd') {
			return 'alt';
		} else {
			if (OS === OperatingSystem.Macintosh) {
				return 'meta';
			} else {
				return 'ctrl';
			}
		}
	}