code: def download(args):
      
      session = c.Session(args)
      issues = aux.parse_for_download(args)
      if issues == ['']:
          sys.exit(
              "You need to give a list of issues, of the form ""a, b-c, d...""")
      dumpfilename = os.path.join(session.data_dir, 'feeddump')
      if not os.path.isfile(dumpfilename):
          sys.exit(
              ("You need to run ""greg check"
               "<feed>"" before using ""greg download""."))
      with open(dumpfilename, mode='rb') as dumpfile:
          dump = pickle.load(dumpfile)
      try:
          feed = c.Feed(session, dump[0], dump[1])
      except Exception:
          sys.exit((
              "... something went wrong."
              "Are you sure your last ""greg check"" went well?"))
      for number in issues:
          entry = dump[1].entries[eval(number)]
          feed.info = []
          feed.entrylinks = []
          feed.fix_linkdate(entry)
          feed.download_entry(entry)
docs: Implement the 'greg download' command