code: def main():
      args = get_user_args()
  
      # for each specified folder
      for experiment_name in args.experiment_names:
          out_dir = os.path.join(
              args.file_dir, experiment_name, "niftynet_data"
          )
          if not os.path.isdir(out_dir):
              os.makedirs(out_dir)
  
          for root, _, files in os.walk(
              os.path.join(args.file_dir, experiment_name)
          ):
              for name in [f for f in files if "track" not in f]:
                  if (
                      "niftynet_data" not in root
                  ):  # don't look at the ones that are done already
                      cell_id = root.split(os.sep)[
                          root.split("/").index(experiment_name) + 1
                      ][:2]
                      out_name = (
                          name.replace("t0", "img_0")
                          .replace("t1", "img_1")
                          .replace("man_seg", "seg_")
                      )
                      out_name = "".join(
                          [
                              out_name.split(".")[0] + "_",
                              cell_id,
                              ".tif",
                          ]
                      )
                      out_path = os.path.join(out_dir, out_name)
                      copy(os.path.join(root, name), out_path)
  
imports: import os
  from shutil import copy
  import argparse
label_desc: Use image node_id 2 for calling a global function with example usage: main() without return types