src/vs/platform/files/browser/htmlFileSystemProvider.ts/HTMLFileSystemProvider/readFile
class HTMLFileSystemProvider:	async readFile(resource: URI): Promise<Uint8Array> {
		const handle = await this.getFileHandle(resource);

		if (!handle) {
			throw new Error('File not found.');
		}

		const file = await handle.getFile();
		return new Uint8Array(await file.arrayBuffer());
	}