How to use the @datorama/akita.guid function in @datorama/akita

upsert(page: Page) {
    if (!page.id) page.id = guid();
    this.store.upsert(page.id, page);
  }

add(page?: Page) {
    const newPage: Page = {
      id: guid(),
      pageTitle: 'New Page',
      pageTags: [],
      blocks: [],
      ...page
    };
    this.store.add(newPage);
  }

export async function addTodo(title) {
  const todo = {
    title,
    completed: false,
  };
  const idFromServer = await Promise.resolve(guid());
  todosStore.add({
    id: idFromServer,
    ...todo
  });
}

export function createTodo(title: Todo['title']) {
  return {
    id: guid(),
    title,
    completed: false
  } as Todo;
}