'Return 400 if the volume exists but has snapshots.'

def test_unmanage_volume_with_snapshots(self):

    vol = utils.create_volume(self.ctxt)
    snap = utils.create_snapshot(self.ctxt, vol.id)
    res = self._get_resp(vol.id)
    self.assertEqual(http_client.BAD_REQUEST, res.status_int, res)
    db.volume_destroy(self.ctxt, vol.id)
    db.snapshot_destroy(self.ctxt, snap.id)
