src/vs/workbench/contrib/welcomeGettingStarted/browser/gettingStartedService.ts/WalkthroughsService/getStep
class WalkthroughsService:	private getStep(id: string): IWalkthroughStep {
		const step = this.steps.get(id);
		if (!step) { throw Error('Attempting to access step which does not exist in registry ' + id); }
		return step;
	}