this.command = requireNonNull(command, "command");
            this.commandName = requireNonNull(commandName, "commandName");
            this.args = requireNonNull(args, "args");
            this.messageBuilderFactory = requireNonNull(messageBuilderFactory, "messageBuilderFactory");
            this.logger = new AccumulatingLogger();

     *
     * @return the user's home directory path
     */
    @Nonnull
    Path userHomeDirectory();

    /**
     * Shorthand for {@link MessageBuilderFactory}.
     */
    default MessageBuilderFactory messageBuilderFactory() {
        return parserRequest().messageBuilderFactory();
    }

    /**
     * Shorthand for {@link Lookup}.
     */
    default Lookup lookup() {
        return parserRequest().lookup();