src/vs/workbench/contrib/debug/browser/callStackView.ts/CallStackDelegate/getTemplateId
class CallStackDelegate:	getTemplateId(element: CallStackItem): string {
		if (isDebugSession(element)) {
			return SessionsRenderer.ID;
		}
		if (element instanceof Thread) {
			return ThreadsRenderer.ID;
		}
		if (element instanceof StackFrame) {
			return StackFramesRenderer.ID;
		}
		if (typeof element === 'string') {
			return ErrorsRenderer.ID;
		}
		if (element instanceof ThreadAndSessionIds) {
			return LoadMoreRenderer.ID;
		}

		// element instanceof Array
		return ShowMoreRenderer.ID;
	}