what is prefer way to add relation and remove relation? I found example as below, but I did't find any document about the two methods.

 case 'ADD_AUTHOR_TO_BOOK':
        Book.withId(action.payload.bookId).authors.add(action.payload.author);  // add new entity ,  add relation?  this doesn't work.
        break;
    case 'REMOVE_AUTHOR_FROM_BOOK':
        Book.withId(action.payload.bo

It would be great to have a couple of example apps, similar to Redux and co. inside an examples folder in the repo.

Also for iPad.

This should fail because otherNum is not part of the State interface:

interface State {
  num: number
}

export const initialState: State = {
  num: 0
};

export const appsReducer = createReducer(initialState, handleAction => [
  handleAction(actions.getApps.success, () => ({
    num: 0,
    otherNum: 0 // adding this property should trigger a warning
  })),
]);