showNotification in react-admin doesn't work, Still : <p><a href="https://codesandbox.io/s/simple-6nzp0" rel="nofollow noreferrer">https://codesandbox.io/s/simple-6nzp0</a>
please see /src/posts/postEdit.js line 73.
no notification show.</p>

<p>Could you add a working code on the sandbox?</p>

<p>though there are other discussion:
<a href="https://stackoverflow.com/questions/54062100/shownotification-in-react-admin-doesnt-work">showNotification in react-admin doesn&#39;t work</a>
<a href="https://github.com/marmelab/react-admin/issues/3402" rel="nofollow noreferrer">https://github.com/marmelab/react-admin/issues/3402</a>
they all did not work.</p>

<p>I need a working code on the sandbox so I know what I miss.</p>

<p>Thanks.</p>
