code: def scan_config_argument(ctx, param, value, config_dir=None):
      
      if callable(config_dir):
          config_dir = config_dir()
  
      if not config:
          click.echo("Enter at least one CONFIG")
          click.echo(ctx.get_help(), color=ctx.color)
          ctx.exit()
  
      if isinstance(value, string_types):
          value = scan_config(value, config_dir=config_dir)
  
      elif isinstance(value, tuple):
          value = tuple([scan_config(v, config_dir=config_dir) for v in value])
  
      return value
docs: Validate / translate config name/path values for click config arg.
  
      Wrapper on top of :func:`cli.scan_config`.