src/vs/workbench/services/userData/common/fileUserDataProvider.ts/FileUserDataProvider/readFileStream
class FileUserDataProvider:	readFileStream(resource: URI, opts: FileReadStreamOptions, token: CancellationToken): ReadableStreamEvents<Uint8Array> {
		if (hasFileReadStreamCapability(this.fileSystemProvider)) {
			return this.fileSystemProvider.readFileStream(this.toFileSystemResource(resource), opts, token);
		}
		throw new Error('not supported');
	}