searchProducts = action$ =>
  action$.ofType(actions.GET_ALL_PRODUCTS).switchMap(q =>
    /*
     * This example uses the same api of the redux-saga example, thus
     * it adapts a Promise to an Observable.
     */
    api.getProducts().map(actions.receiveProducts)
  )
search products epic
@param action$
@param store
@returns {any|*|Observable}