code: def pool2d_cx(cx, in_c, k, *, stride=1):
      """Accumulates complexity of pool2d into cx = (h, w, flops, params, acts)."""
      assert (
          k % 2 == 1
      ), "Only odd size kernels supported to avoid padding issues."
      h, w, c = cx["h"], cx["w"], cx["c"]
      assert c == in_c
      h, w = (h - 1) // stride + 1, (w - 1) // stride + 1
      cx["h"] = h
      cx["w"] = w
      cx["acts"] += in_c * h * w
      return cx
  
label_desc: Use image node_id 2 for calling a global function with example usage: pool2d_cx(cx, in_c, k) and returns: cx