protected function insertKey(Channel $chan, TreeUpdate $update)
{
$supplier = $update->getSupplier();
$name = $supplier->getName();
$file = ROOT . '/config/supplier_keys/' . $name . '.json';
$supplierData = \Airship\loadJSON($file);
$supplierData['signing_keys'][] = ['type' => $update->getKeyType(), 'public_key' => $update->getPublicKeyString()];
\Airship\saveJSON($file, $supplierData);
\clearstatcache();
// Flush the channel's supplier cache
$chan->getSupplier($name, true);
}