code: def main():
      parser = optparse.OptionParser(
          "usage: %prog [options] /path/to/existing/venv /path/to/cloned/venv"
      )
      parser.add_option(
          "-v",
          action="count",
          dest="verbose",
          default=False,
          help="verbosity",
      )
      options, args = parser.parse_args()
      try:
          old_dir, new_dir = args
      except ValueError:
          print("virtualenv-clone %s" % (__version__,))
          parser.error("not enough arguments given.")
      old_dir = os.path.realpath(old_dir)
      new_dir = os.path.realpath(new_dir)
      loglevel = (logging.WARNING, logging.INFO, logging.DEBUG)[
          min(2, options.verbose)
      ]
      logging.basicConfig(level=loglevel, format="%(message)s")
      try:
          clone_virtualenv(old_dir, new_dir)
      except UserError:
          e = sys.exc_info()[1]
          parser.error(str(e))
  
imports: from __future__ import with_statement
  import logging
  import optparse
  import os
  import os.path
  import re
  import shutil
  import subprocess
  import sys
  import itertools
label_desc: Use image node_id 13 for calling a global function with example usage: main() without return types