code: def forward(self, net: Tensor) -> Tensor:
      if self.conv is None:
          return F.avg_pool2d(net, kernel_size=2, stride=2)
      pad = (0, 1, 0, 1)
      net = F.pad(net, pad, mode="constant", value=0)
      net = self.conv(net)
      return net
  
file_path: carefree-learn/cflearn/models/cv/encoder/attn.py
imports: import torch.nn
  import torch.nn.functional
  from torch import Tensor
  from typing import Tuple
  from .schema import EncoderMixin
  from ....modules.blocks import make_attention
  from ....modules.blocks import HijackConv2d
  from ....modules.blocks import ResidualBlockWithTimeEmbedding
label_desc: Use image node_id 2 for calling the Downsample obj's underlying member method code with example usage: obj.forward(net) and returns: net, F