code: def create_split_dir(source_dir, split_dir):
      dataset = MAG240MDataset(source_dir)
      split_dir_exists = os.path.exists(split_dir)
      if not split_dir_exists:
          os.mkdir(split_dir)
  
      valid_idx = dataset.get_idx_split("valid")
      np.random.seed(999)
      np.random.shuffle(valid_idx)
      end = len(valid_idx)
      part = len(valid_idx) // 5 + 1
  
      for idx, x in enumerate(range(0, end, part)):
          y = min(x + part, end)
          valid_part = valid_idx[x:y]
          print(valid_part.shape)
          split_file = f"{split_dir}/valid_{idx}"
          np.save(split_file, valid_part)
  
imports: import numpy
  from ogb.lsc import MAG240MDataset
  import os
label_desc: Use image node_id 1 for calling a global function with example usage: create_split_dir(source_dir, split_dir) without return types