Javascript 将redux observable集成到现有项目中-未捕获类型错误：无法读取属性'；应用'；未定义的

我试图将redux observable集成到现有的redux项目中，方法是绕过现有的拦截器进行简单的操作，并将其传递给一个新的epic，该epic当前应该只映射到一个新的操作类型。我得到了一个错误：

Uncaught TypeError: Cannot read property 'apply' of undefined
    at app.js:217853
    at Array.map (<anonymous>)
    at merger (app.js:217852)
    at MapSubscriber.project (app.js:217918)
    at MapSubscriber../node_modules/rxjs/_esm5/internal/operators/map.js.MapSubscriber._next (app.js:225604)
    at MapSubscriber../node_modules/rxjs/_esm5/internal/Subscriber.js.Subscriber.next (app.js:220361)
    at Subject../node_modules/rxjs/_esm5/internal/Subject.js.Subject.next (app.js:220127)
    at Function.epicMiddleware.run (app.js:217952)
    at GenericProvider../src/bootstrap/bootstrapStore.js.exports.default [as $get] (app.js:299968)
    at Object.getService (app.js:46915)

其中，

registry.rootEpic

是使用BottleJS引导的：

bottle.factory('rootEpic', require('./bootstrapRootEpic').default);
bottle.factory('store', require('./bootstrapStore').default);

bootstrapRootEpic.js如下所示：

import { combineEpics } from 'redux-observable';

import { createExercisesEpic } from 'src/actions/epics';

export default function(registry) {
  return combineEpics(createExercisesEpic);
}

import { mapTo } from 'rxjs/operators';
import { ofType } from 'redux-observable';

import {
  CREATE_EXERCISES,
  CREATE_EXERCISES_COMPLETED
} from 'src/actions/types';

export default function(action$) {
  return action$.pipe(
    ofType(CREATE_EXERCISES),
    mapTo({type: CREATE_EXERCISES_COMPLETED})
  );
}

createExercisePics

在src/actions/epics/index.js中定义：

export default {
  createExercisesEpic: require('./createExercisesEpic').default
};

createExecuteSepic.js如下所示：

import { combineEpics } from 'redux-observable';

import { createExercisesEpic } from 'src/actions/epics';

export default function(registry) {
  return combineEpics(createExercisesEpic);
}

import { mapTo } from 'rxjs/operators';
import { ofType } from 'redux-observable';

import {
  CREATE_EXERCISES,
  CREATE_EXERCISES_COMPLETED
} from 'src/actions/types';

export default function(action$) {
  return action$.pipe(
    ofType(CREATE_EXERCISES),
    mapTo({type: CREATE_EXERCISES_COMPLETED})
  );
}

---

我是否遗漏了某个步骤，或者可能是某个变量定义不正确或意外未定义？

问题在于我试图使用此导入样式：

import { createExercisesEpic } from 'src/actions/epics';

它仅适用于作为函数导出的函数，而不是作为导出对象的命名特性导出的函数。我把它改成：

import epics from 'src/actions/epics';

export default function(registry) {
  return epics.createExercisesEpic;
}

---

如果你能提供一个