src/transformers/models/swin2sr/modeling_swin2sr.py/UpsampleOneStep/__init__
class UpsampleOneStep:    def __init__(self, scale, in_channels, out_channels):
        super().__init__()

        self.conv = nn.Conv2d(in_channels, (scale**2) * out_channels, 3, 1, 1)
        self.pixel_shuffle = nn.PixelShuffle(scale)