public function testFlushAll() {
$cache = $this
->_getCacheDriver();
$cache
->save('test_key1', '1');
$cache
->save('test_key2', '2');
$cache
->flushAll();
$this
->assertFalse($cache
->contains('test_key1'));
$this
->assertFalse($cache
->contains('test_key2'));
}