public function testUpdate()
 {
     $container = $this->getContainerMock();
     $dataObject = $this->getDataObjectMock('filename.ext');
     $dataObject->shouldReceive('setContent');
     $dataObject->shouldReceive('setEtag');
     $dataObject->shouldReceive('update')->andReturn(Mockery::self());
     $container->shouldReceive('getObject')->andReturn($dataObject);
     $adapter = new Rackspace($container);
     $this->assertInternalType('array', $adapter->update('filename.ext', 'content', new Config()));
 }