extensions/json-language-features/server/src/node/jsonServerMain.ts/getFileRequestService
function getFileRequestService(): RequestService {
	return {
		getContent(location: string, encoding?: BufferEncoding) {
			return new Promise((c, e) => {
				const uri = Uri.parse(location);
				fs.readFile(uri.fsPath, encoding, (err, buf) => {
					if (err) {
						return e(err);
					}
					c(buf.toString());
				});
			});
		}
	};
}