public function testAttachVolume()
 {
     $volume = new Swagger\Client\Model\Volume();
     $props = new \Swagger\Client\Model\VolumeProperties();
     $props->setName("test-volume")->setSize(3)->setType('HDD')->setLicenceType('LINUX');
     $volume->setProperties($props);
     $testVolume = self::$volume_api->create(self::$testDatacenter->getId(), $volume);
     self::$testVolume = self::assertPredicate(function ($testVolume) {
         $volume = self::$volume_api->findById(self::$testDatacenter->getId(), $testVolume->getId());
         if ($volume->getMetadata()->getState() == 'AVAILABLE') {
             return $volume;
         }
     }, array($testVolume));
     $this->assertEquals(self::$testVolume->getProperties()->getSize(), 3);
     $volume = new Swagger\Client\Model\Volume();
     $volume->setId(self::$testVolume->getId());
     self::$attached_volume_api->attachVolume(self::$testDatacenter->getId(), self::$testServer->getId(), $volume);
     self::assertPredicate(function ($testVolume) {
         return self::$attached_volume_api->findById(self::$testDatacenter->getId(), self::$testServer->getId(), self::$testVolume->getId());
     }, array($testVolume));
 }