@Override
  public void setEntities(Collection<ShoppingList> entities) {

    mShoppingListMap = new HashMap<>();
    for (ShoppingList entity : entities) {
      mShoppingListMap.put(entity.getId(), entity);
    }
  }
  @Override
  public void updateEntity(ShoppingList entity) {

    mShoppingListMap.put(entity.getId(), entity);
  }