TransformStream
interface TransformStream <I = any, O = any> {
readonly readable: ReadableStream<O>;
readonly writable: WritableStream<I>;
}var TransformStream: {
prototype: TransformStream;
new <I = any, O = any>(
};transformer?: Transformer<I, O>,
writableStrategy?: QueuingStrategy<I>,
readableStrategy?: QueuingStrategy<O>,
): TransformStream<I, O>;