\right\rfloor
  W_{out} = \left\lfloor W_{in} \times \text{scale\_factor}
  \right\rfloor

Examples:
  >>> input = torch.arange(1, 5, dtype=torch.float32).view(1, 1, 2, 2)
  >>> input
  tensor([[[[1., 2.],
            [3., 4.]]]])

  >>> m = nn.UpsamplingBilinear2d(scale_factor=2)
  >>> m(input)
  tensor([[[[1.0000, 1.3333, 1.6667, 2.0000],
            [1.6667, 2.0000, 2.3333, 2.6667],
            [2.3333, 2.6667, 3.0000, 3.3333],
            [3.0000, 3.3333, 3.6667, 4.0000]]]])
