text: const _DEFAULT_KEY = 'ALL';
  
  export const initialState = {
    data: {},
    unitIdMap: {},
  
    isFetchingBooks: false,
  };
  
  export const createInitialDataState = () => ({
    itemIdsForPage: {},
    items: {},
    totalCount: 0,
  });
  
  export const getKey = () => _DEFAULT_KEY;
  