* there are no elements left in the iteration. Failure to do so could result in an infinite loop.
   *
   * <p>The initial invocation of {@link #hasNext()} or {@link #next()} calls this method, as does
   * the first invocation of {@code hasNext} or {@code next} following each successful call to
   * {@code next}. Once the implementation either invokes {@code endOfData} or throws an exception,

   * there are no elements left in the iteration. Failure to do so could result in an infinite loop.
   *
   * <p>The initial invocation of {@link #hasNext()} or {@link #next()} calls this method, as does
   * the first invocation of {@code hasNext} or {@code next} following each successful call to
   * {@code next}. Once the implementation either invokes {@code endOfData} or throws an exception,

      state = State.READY;
      return true;
    }
    return false;
  }

  @Override
  @ParametricNullness
  public final T next() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }
    state = State.NOT_READY;
    // Safe because hasNext() ensures that tryToComputeNext() has put a T into `next`.
    T result = uncheckedCastNullableTToT(next);
    next = null;
    return result;
  }

      state = State.READY;
      return true;
    }
    return false;
  }

  @Override
  @ParametricNullness
  public final T next() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }
    state = State.NOT_READY;
    // Safe because hasNext() ensures that tryToComputeNext() has put a T into `next`.
    T result = uncheckedCastNullableTToT(next);
    next = null;
    return result;
  }