public function testWriteNoExpiry()
{
$keys = array('key1' => 'data1');
$adapter = new XCache(array('expiry' => null));
$expiry = null;
$result = $adapter->write($keys, $expiry);
$this->assertTrue($result);
$result = xcache_isset('key1');
$this->assertTrue($result);
xcache_unset('key1');
$adapter = new XCache(array('expiry' => Cache::PERSIST));
$expiry = Cache::PERSIST;
$result = $adapter->write($keys, $expiry);
$this->assertTrue($result);
$result = xcache_isset('key1');
$this->assertTrue($result);
xcache_unset('key1');
$adapter = new XCache();
$expiry = Cache::PERSIST;
$result = $adapter->write($keys, $expiry);
$this->assertTrue($result);
$result = xcache_isset('key1');
$this->assertTrue($result);
}