code: def iterate(val=True, shuffle=False):
      if not val:
          raise NotImplementedError
      files = get_val_files()
      order = list(range(0, len(files)))
      if shuffle:
          random.shuffle(order)
      for file in files:
          X, Y = preprocess(file)
          X = np.expand_dims(X, axis=0)
          yield (X, Y)
  
file_path: tinygrad/extra/datasets/kits19.py
imports: import random
  import functools
  from pathlib import Path
  import numpy
  import nibabel
  from scipy import signal
  import torch
  import torch.nn.functional
  from tinygrad.tensor import Tensor
  from tinygrad.helpers import fetch
label_desc: Use image node_id 7 for calling a global function with example usage: iterate(val, shuffle) without return types