public function testSetAndGetExpiredItems()
 {
     $capabilities = $this->_storage->getCapabilities();
     $ttl = $capabilities->getTtlPrecision();
     $this->_options->setTtl($ttl);
     $items = array('key1' => 'value1', 'key2' => 'value2', 'key3' => 'value3');
     $this->assertTrue($this->_storage->setItems($items));
     // wait until expired
     $wait = $ttl + $capabilities->getTtlPrecision();
     usleep($wait * 2000000);
     $rs = $this->_storage->getItems(array_keys($items));
     if (!$capabilities->getUseRequestTime()) {
         $this->assertEquals(array(), $rs);
     } else {
         ksort($rs);
         $this->assertEquals($items, $rs);
     }
     if ($capabilities->getExpiredRead()) {
         $rs = $this->_storage->getItems(array_keys($items), array('ttl' => 0));
         ksort($rs);
         $this->assertEquals($items, $rs);
     }
 }