def METHOD_NAME(self):
    img_shape = [50, 85]
    # horizontal flip
    th_boxes = torch.Tensor([10, 10, 20, 20]).reshape(1, 1, 4)
    flipped_boxes_th = torch.Tensor([65, 10, 75, 20]).reshape(1, 1, 4)
    boxes = HorizontalBoxes(th_boxes)
    boxes.flip_(img_shape, direction='horizontal')
    assert_allclose(boxes.tensor, flipped_boxes_th)
    # vertical flip
    th_boxes = torch.Tensor([10, 10, 20, 20]).reshape(1, 1, 4)
    flipped_boxes_th = torch.Tensor([10, 30, 20, 40]).reshape(1, 1, 4)
    boxes = HorizontalBoxes(th_boxes)
    boxes.flip_(img_shape, direction='vertical')
    assert_allclose(boxes.tensor, flipped_boxes_th)
    # diagonal flip
    th_boxes = torch.Tensor([10, 10, 20, 20]).reshape(1, 1, 4)
    flipped_boxes_th = torch.Tensor([65, 30, 75, 40]).reshape(1, 1, 4)
    boxes = HorizontalBoxes(th_boxes)
    boxes.flip_(img_shape, direction='diagonal')
    assert_allclose(boxes.tensor, flipped_boxes_th)