code: def main():
      args = parse_args()
  
      logging.basicConfig(level=logging.DEBUG)
      logging.debug(args)
  
      num_bad = 0
  
      for line in sys.stdin:
          tokens = line.strip().split(" ")
  
          if tokens[0][0] == "<" and tokens[0][-1] == ">":
              logging.warning(
                  "First token of sentence already seems to be a special language tag: '%s'."
                  % tokens[0]
              )
              num_bad += 1
  
          if tokens[0] == args.tag:
              logging.error(
                  "Sentence already has '%s' as first token. Do not run this script twice."
                  % args.tag
              )
              sys.exit(1)
          else:
              tokens = [args.tag] + tokens
  
          line = " ".join(tokens)
  
          print(line)
  
      if num_bad > 0:
          logging.debug(
              "Number of times sentences had a first token of the form '<...>': %d."
              % num_bad
          )
  
imports: import sys
  import argparse
  import logging
label_desc: Use image node_id 2 for calling a global function with example usage: main() without return types