old_contents: import sys
  import argparse
  import os
  
  def main(arguments=None):
      if arguments == None:
          arguments = sys.argv[1:]
  
  if __name__ == "__main__":
      main()
  
new_contents: import sys
  import argparse
  import os
  import mediachain.api
  
  def main(arguments=None):
      if arguments == None:
          arguments = sys.argv[1:]
  
      parser = argparse.ArgumentParser(
          prog='mediachain-reader',
          description='Mediachain Reader CLI'
      )
      subparsers = parser.add_subparsers(help='Mediachain Reader SubCommands',
                                         dest='subcommand')
  
      get_parser = subparsers.add_parser(
          'get',
          help='Get a revision chain for a given artefact/entity id'
      )
      get_parser.add_argument('object_id',
                              type=str,
                              help='The id of the artefact/entity to fetch')
  
      ns = parser.parse_args(arguments)
      fn = getattr(mediachain.api, ns.subcommand)
      fn(ns)
  
  if __name__ == "__main__":
      main()
  
subject: Add arg parsing