code: def forward(self, x: torch.Tensor) -> torch.Tensor:
      if self.main is None:
          res = x
      elif self.shortcut is None:
          res = self.forward_main(x)
      else:
          res = self.forward_main(x) + self.shortcut(x)
          if self.post_act:
              res = self.post_act(res)
      return res
  
imports: from __future__ import annotations
  import torch
  import torch.nn.functional
  from torch import nn
  from torch.cuda.amp import autocast
  from kornia.contrib.models.efficient_vit.nn.act import build_act
  from kornia.contrib.models.efficient_vit.nn.norm import build_norm
  from kornia.contrib.models.efficient_vit.utils import get_same_padding, val2tuple
label_desc: Use image node_id 3 for calling the ResidualBlock obj's underlying member method code with example usage: obj.forward(x) and returns: res