public function testWriteExpiryExpires()
{
$keys = array('key1' => 'data1');
$expiry = '+5 seconds';
$this->redis->write($keys, $expiry);
$result = $this->_redis->exists('key1');
$this->assertTrue($result);
$this->_redis->delete('key1');
$keys = array('key1' => 'data1');
$expiry = '+1 second';
$this->redis->write($keys, $expiry);
sleep(2);
$result = $this->_redis->exists('key1');
$this->assertFalse($result);
}