code: def check_args(args):
      assert (
          args.rpn_pkl is not None and args.rpn_cfg is not None
      ) or (args.rpn_pkl is None and args.rpn_cfg is None)
      if args.rpn_pkl is not None:
          args.rpn_pkl = cache_url(args.rpn_pkl, cfg.DOWNLOAD_CACHE)
          assert os.path.exists(args.rpn_pkl)
          assert os.path.exists(args.rpn_cfg)
      if args.models_to_run is not None:
          assert len(args.models_to_run) % 2 == 0
          for i, model_file in enumerate(args.models_to_run):
              if len(model_file) > 0:
                  if i % 2 == 0:
                      model_file = cache_url(
                          model_file, cfg.DOWNLOAD_CACHE
                      )
                      args.models_to_run[i] = model_file
                  assert os.path.exists(
                      model_file
                  ), "'{}' does not exist".format(model_file)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import argparse
  import cv2
  import logging
  import os
  import sys
  import yaml
  from caffe2.python import workspace
  from detectron.core.config import assert_and_infer_cfg
  from detectron.core.config import cfg
  from detectron.core.config import load_cfg
  from detectron.core.config import merge_cfg_from_cfg
  from detectron.core.config import merge_cfg_from_file
  from detectron.utils.io import cache_url
  from detectron.utils.logging import setup_logging
  import detectron.core.rpn_generator
  import detectron.core.test_engine
  import detectron.datasets.dummy_datasets
  import detectron.utils.c2
  import detectron.utils.vis
label_desc: Use image node_id 4 for calling a global function with example usage: check_args(args) without return types