Invalid arguments passed in implode() line 52 of apc/apc.module

After enabling debug mode, this message appears in watchdog.
Its probably because apc is not yet running for me, but anyway, in apc_shutdown(), one should probably check that $apc_statistics is set before trying to print it out in the following code - to avoid the above warning.
foreach ($apc_statistics as $row) {
$row[2] = implode(',
', $row[2]);
$rows[] = $row;
}