code: def __call__(self, x):
      x = self.input_block(x)
      outputs = [x]
      for downsample in self.downsample:
          x = downsample(x)
          outputs.append(x)
      x = self.bottleneck(x)
      for upsample, skip in zip(self.upsample, outputs[::-1]):
          x = upsample(x, skip)
      x = self.output["conv"](x)
      return x
  
file_path: tinygrad/extra/models/unet3d.py
imports: from pathlib import Path
  import torch
  from tinygrad import nn
  from tinygrad.tensor import Tensor
  from tinygrad.helpers import fetch, get_child
label_desc: Use image node_id 2 for calling the UNet3D obj's underlying member method code with example usage: obj.__call__(x) and returns: x