element ui 在 vuecli3 中如何配置按需加载？

Question

element ui 在 vuecli3 中如何配置按需加载？

cli3 默认 devDependencies

  "devDependencies": {
    "@vue/cli-plugin-babel": "^3.0.0-rc.5",
    "@vue/cli-plugin-eslint": "^3.0.0-rc.5",
    "@vue/cli-service": "^3.0.0-rc.5",
    "@vue/eslint-config-standard": "^3.0.0-rc.5",
    "node-sass": "^4.9.0",
    "sass-loader": "^7.0.1",
    "vue-template-compiler": "^2.5.16"
  }