parcel hot module replacement problem

I'm just started to explore `the-platform` library. For contribution, I fork the repository and then clone it to local machine. In `example` folder, I run a command `yarn start` which open live server on port `http://localhost:1234/`. If made changes to `example/App.js` file then `parceljs` (hot module replacement) doesn't remove an old component from DOM.

I think this problem with `parceljs`. May be we have to toggle configuration of `parceljs`

Start by running yarn start in the example folder and reproduce the hot module replacement behavior after editing example/App.js. Inspect the Parcel-related setup used by that command and determine why the previous component remains in the DOM; done means an edit no longer leaves the old component behind.

Written by the indexing model from the issue text.