docs: def cmd_help(self, argv, help):
          """Print help"""
          parser = argparse.ArgumentParser(
              prog="%s help" % self.progname,
              description=help,
          )
          parser.add_argument('-z', '--zsh',
                              action='store_true',
                              help="Print info for zsh autocompletion")
          parser.add_argument("command", nargs='?',
                              metavar="command",
                              help="Name of the command you want help for.",
                              choices=self.subparsers.keys())
          args = parser.parse_args(argv)
          if args.zsh:
              if args.command is None:
                  for cmd in self.subparsers.keys():
                      print(cmd)
              else:  # pragma: no cover
                  if hasattr(self.cmds[args.command], 'get_completion'):
                      for item in self.cmds[args.command].get_completion():
                          print(item)
                  elif args.command in ('do', 'ssh'):
                      for instance in self.get_instances(command='init_ssh_key'):
                          print(instance)
                  elif args.command == 'debug':
                      for instance in sorted(self.instances):
                          print(instance)
                  elif args.command == 'list':
                      for subcmd in sorted(self.list_cmds):
                          print(subcmd)
                  elif args.command != 'help':
                      for instance in sorted(self.get_instances(command=args.command)):
                          print(instance)
          else:
              if args.command is None:
                  parser.print_help()
              else:
                  cmd = self.cmds[args.command]
                  cmd(['-h'], cmd.__doc__)