code: function parseSubArgs (args, parsed) {
    let arg = args[0];
  
    if (arg === "[") {
      while (arg !== "]") {
        arg = args.shift();
        parsed.args.push(arg);
      }
      return true;
    }
  }
docs: If the current argument is a sub-argument list,
  then this function shifts the whole list to {@link ParsedArgs#args}.
  
  @param {string[]} args - The command-line arguments that have not yet been parsed
  @param {ParsedArgs} parsed - The command-line arguments that have already been parsed
  @returns {boolean}