extensions/json-language-features/client/src/node/schemaCache.ts/JSONSchemaCache/loadSchemaFile
class JSONSchemaCache:	private async loadSchemaFile(schemaUri: string, cacheEntry: CacheEntry, isUpdated: boolean): Promise<string | undefined> {
		const cacheLocation = path.join(this.schemaCacheLocation, cacheEntry.fileName);
		try {
			const content = (await fs.readFile(cacheLocation)).toString();
			if (isUpdated) {
				cacheEntry.updateTime = new Date().getTime();
			}
			return content;
		} catch (e) {
			delete this.cacheInfo[schemaUri];
			return undefined;
		} finally {
			await this.updateMemento();
		}
	}