Is the self-shunt pattern the same as stubbing in TDD?

I am reading the book TDD by Example and one of the patterns demonstrated was the self-shunt pattern.

Basically, if I am not mistaken, if I have a test like this:

test("list of users should receive a new user"), () => {
  const user = new User()
  const listOfUsers = new ListOfUsers()
  listOfUsers.insert(user)
}

Then, the only way to know if listOfUsers actually received the user, is to stub it, correct?

class ListOfUsersStub {
  constructor () {
    this.users = []
  }

  insert (user) {
    this.users.push(user)
    return this.users
  }
}

then I can test it so:

test("list of users should receive a new user"), () => {
  const user = new User()
  const listOfUsers = new ListOfUsers()
  const result = listOfUsers.insert(user)
  expect(result.users).toContain(user)
}

Is this the same as the self shunt pattern? Or am I missing something?

Thanks