code: def download(datapath):
      opt = {"datapath": datapath}
      model_name = "unittest"
      mdir = os.path.join(get_model_dir(datapath), model_name)
      version = "v7.1"
      model_filenames = [
          "seq2seq.tar.gz",
          "transformer_ranker.tar.gz",
          "transformer_generator2.tar.gz",
          "memnn.tar.gz",
          "apex_v1.tar.gz",
          "test_bytelevel_bpe_v2.tar.gz",
          "beam_blocking1.tar.gz",
          "context_blocking1.tar.gz",
          "hred_model_v1.tar.gz",
      ]
      if not built(mdir, version):
          download_models(
              opt, model_filenames, model_name, version=version
          )
  
label_desc: Use image node_id 1 for calling a global function with example usage: download(datapath) without return types