public function testWriteExpiryDefault()
{
$apc = new Apc(array('expiry' => '+5 seconds'));
$keys = array('key1' => 'data1');
$expiry = null;
$result = $apc->write($keys, $expiry);
$this->assertTrue($result);
$result = apc_exists('key1');
$this->assertTrue($result);
}