src/vs/workbench/services/history/browser/historyService.ts/EditorNavigationStack/traceEvent
class EditorNavigationStack:	private traceEvent(event?: IEditorPaneSelectionChangeEvent): string {
		if (!event) {
			return '<none>';
		}

		switch (event.reason) {
			case EditorPaneSelectionChangeReason.EDIT: return 'edit';
			case EditorPaneSelectionChangeReason.NAVIGATION: return 'navigation';
			case EditorPaneSelectionChangeReason.JUMP: return 'jump';
			case EditorPaneSelectionChangeReason.PROGRAMMATIC: return 'programmatic';
			case EditorPaneSelectionChangeReason.USER: return 'user';
		}
	}