javascript - When using Mint-UI, this.$toast() can be used, but the this object does not see $toast. What's going on?

Question

In main.js:
Vue.use(MintUI)
Vue.use(VueRouter)

Use in the vue instance:
console.log(this);
You can see $route and $router, etc.
I don’t see mintUI components such as $toast,
but I can use this.$toast();
Where does the $toast here come from?

Answer 1

Open the prototype and see if there is any