code: def list_categories(tag):
      url = "http://lsun.cs.princeton.edu/htbin/list.cgi?tag=" + tag
      f = urlopen(url)
      return json.loads(f.read())
  
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 1 for calling a global function with example usage: list_categories(tag) and returns: json