packages/mesh/lib/streams/std/readable-stream.js
function ReadableStreamReaderGenericCancel(reader, reason) {
  const stream = reader._ownerReadableStream;
  assert(stream !== undefined);
  return ReadableStreamCancel(stream, reason);
}
function ReadableStreamReaderGenericCancel(reader, reason) {
  const stream = reader._ownerReadableStream;
  assert(stream !== undefined);
  return ReadableStreamCancel(stream, reason);
}
A client of ReadableStreamDefaultReader and ReadableStreamBYOBReader may use these functions directly to bypass state check.