Cache

const cache = cacheService.createCache({  getKey: id => `ProductVariantIds:${id}`,  options: {    ttl: 1000 * 60 * 60,    tags: ['products'],  },});// This will fetch the value from the cache if it exists, or// fetch it from the ProductService if not, and then cache// using the key 'ProductVariantIds.${id}'.const variantIds = await cache.get(id, async () => {  const variants await ProductService.getVariantsByProductId(ctx, id) ;  // The cached value must be serializable, so we just return the ids  return variants.map(v => v.id);});

class Cache {    constructor(config: CacheConfig, cacheService: CacheService)    get(id: string | number, getValueFn: () => T | Promise<T>) => Promise<T>;    delete(id: string | number | Array<string | number>) => Promise<void>;    invalidateTags(tags: string[]) => Promise<void>;}