'An unattached ``BlockDeviceVolume`` can be attached.'

def test_attach_unattached_volume(self):

    dataset_id = uuid4()
    new_volume = self.api.create_volume(dataset_id=dataset_id, size=self.minimum_allocatable_size)
    expected_volume = BlockDeviceVolume(blockdevice_id=new_volume.blockdevice_id, size=new_volume.size, attached_to=self.this_node, dataset_id=dataset_id)
    attached_volume = self.api.attach_volume(blockdevice_id=new_volume.blockdevice_id, attach_to=self.this_node)
    self.assertEqual(expected_volume, attached_volume)
