text: import {combineReducers} from "redux";
  import byId, * as fromById from "./byId";
  import createList, * as fromList from "./CreateList";
  
  const listByFilter = combineReducers({
      all: createList('all'),
      active: createList('active'),
      completed: createList('completed'),
  });
  
  const todos = combineReducers({
      byId,
      listByFilter,
  });
  
  export const getVisibleTodos = (state, filter) => {
      const ids = fromList.getIds(state.listByFilter[filter]);
      return ids.map(id => fromById.getTodo(state.byId, id));
  };
  
  export const getIsFetching = (state, filter) =>
      fromList.getIsFetching(state.listByFilter[filter]);
  
  export const getErrorMessage = (state, filter) =>
      fromList.getErrorMessage(state.listByFilter[filter]);
  
  export default todos;
  