code: def download_lsun(out_dir, category, set_name, tag):
      url = (
          "http://lsun.cs.princeton.edu/htbin/download.cgi?tag={tag}"
          "&category={category}&set={set_name}".format(**locals())
      )
      if set_name == "test":
          out_name = "test_lmdb.zip"
      else:
          out_name = "{category}_{set_name}_lmdb.zip".format(**locals())
      out_path = join(out_dir, out_name)
      download(url, out_path, True)
  
imports: from __future__ import print_function, division
  import argparse
  import json
  from os.path import join
  from gluoncv.utils.download import download
label_desc: Use image node_id 2 for calling a global function with example usage: download_lsun(out_dir, category, set_name, tag) without return types