code: def forward(self, x: Tensor) -> Tensor:
      x = self.stem1(x)
      x = concatenate([self.pool(x), self.stem2b(self.stem2a(x))], 1)
      x = self.stem4(self.stem3(x))
      return x
  
imports: from __future__ import annotations
  from typing import NamedTuple
  from torch import nn
  from kornia.contrib.models.common import ConvNormAct
  from kornia.core import Module, Tensor, concatenate
  from kornia.core.check import KORNIA_CHECK
label_desc: Use image node_id 2 for calling the StemBlock obj's underlying member method code with example usage: obj.forward(x) and returns: x