<blockquote>
<p>I wonder what the callback can be used for.</p>
</blockquote>
<p>Toggle a pin ?</p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly, <a href="https://github.com/RIOT-OS/RIOT/pull/11556?email_source=notifications&email_token=ABE7WYBCOBQBAKOENETYJHTQJD6QFA5CNFSM4HOHWQTKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6OWGGA#issuecomment-530408216">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/ABE7WYFJVRE2I3L6REUAHO3QJD6QFANCNFSM4HOHWQTA">mute the thread</a>.<img src="https://github.com/notifications/beacon/ABE7WYFJG6RQ5P2VJM53NULQJD6QFA5CNFSM4HOHWQTKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6OWGGA.gif" height="1" width="1" alt="" /></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/RIOT-OS/RIOT/pull/11556?email_source=notifications\u0026email_token=ABE7WYBCOBQBAKOENETYJHTQJD6QFA5CNFSM4HOHWQTKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6OWGGA#issuecomment-530408216",
"url": "https://github.com/RIOT-OS/RIOT/pull/11556?email_source=notifications\u0026email_token=ABE7WYBCOBQBAKOENETYJHTQJD6QFA5CNFSM4HOHWQTKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD6OWGGA#issuecomment-530408216",
"name": "View Pull Request"
},
"description": "View this Pull Request on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>