@Override
  public Photo get(Long key)
  {
    return _db.getData().get(key);
  }
@Test
  public void testResourceGet()
  {
    // because the test function will take arbitrary order
    // always create a photo and operate on that photo for a test function
    final Long id = createPhoto();

    // validate all data are correct
    final Photo p = _res.get(id);
    Assert.assertNotNull(p);
    Assert.assertEquals(p.getId(), id);
    Assert.assertTrue(p.hasExif());
    final EXIF e = p.getExif();
    Assert.assertTrue(e.hasLocation());
    final LatLong l = e.getLocation();
    Assert.assertEquals(l.getLatitude(), 7.0f);
    Assert.assertEquals(l.getLongitude(), 27.0f);
  }