src/vs/workbench/services/search/node/ripgrepSearchProvider.ts/RipgrepSearchProvider/withToken
class RipgrepSearchProvider:	private async withToken<T>(token: CancellationToken, fn: (token: CancellationToken) => Promise<T>): Promise<T> {
		const merged = mergedTokenSource(token);
		this.inProgress.add(merged);
		const result = await fn(merged.token);
		this.inProgress.delete(merged);

		return result;
	}