code: function transformRaw(input, options) {
    const transformStream = new TransformStream(options);
    pipe(input, transformStream.writable);
    return transformStream.readable;
  }
docs: Pipe a readable stream through a transform stream.
  @param {ReadableStream|Uint8array|String} input
  @param {Object} (optional) options
  @returns {ReadableStream} transformed stream