如何在模块名称空间中使用Vuex类型常量？

我有这个Vuex模块：

//modules/things.js
const state = {
  firstThing: 'abc',
  secondThing: 'def',
};

const getters = {
  getFirstThing: state => state.firstThing,
  getSecondThing: state => state.secondThing,
};

const mutations = {
  setFirstThing: (state, payload) => state.firstThing = payload,
  setSecondThing: (state, payload) => state.secondThing = payload
};

const actions = {};

export default {
  namespaced: true,   // <------
  state,
  mutations,
  actions,
  getters
};

我使用namespaced: true 标志，并且可以像下面这样使用该模块：

this.$store.state.things.firstThing             // <-- return abc here
this.$store.commit('things/setFirstThing', 10)
this.$store.getters['things/getFirstThing']     // <-- return abc here

如果我将使用Vuex 官方示例中的常量，并modules/things.js像这样重构我的文件：

export const Types = {
  getters: {
    GET_FIRST_THING: 'GET_FIRST_THING',
    GET_SECOND_THING: 'GET_SECOND_THING',
  },
  mutations: {
    SET_FIRST_THING: 'SET_FIRST_THING',
    SET_SECOND_THING: 'SET_SECOND_THING',
  }
};

const getters = {
  [Types.getters.GET_FIRST_THING]: state => state.firstThing,
  [Types.getters.GET_SECOND_THING]: state => state.secondThing,
};

const mutations = {
  [Types.mutations.SET_FIRST_THING]: (state, payload) => state.firstThing = payload,
  [Types.mutations.SET_SECOND_THING]: (state, payload) => state.secondThing = payload
};

我将不得不使用名称空间前缀：

this.$store.commit('things/' + Types.mutations.SET_FIRST_THING, 10);
this.$store.getters['things/' +  + Types.getters.GET_FIRST_THING]  

如果我将模块名称空间前缀包括在Types常量中，则必须使用字符串前缀things/进行突变/动作/获取器声明：

const getters = {
  ['things/' + Types.getters.GET_FIRST_THING]: state => state.firstThing,
  ['things/' + Types.getters.GET_SECOND_THING]: state => state.secondThing,
};

如何避免呢？