public void sendUsage(Sender sender) {
        TextComponent.Builder builder = Component.text()
                .append(Component.text('>', NamedTextColor.DARK_AQUA))
                .append(Component.space())
                .append(Component.text(getName().toLowerCase(Locale.ROOT), NamedTextColor.GREEN));

        if (getArgs() != null) {
            List<Component> argUsages = getArgs().stream()
                    .map(Argument::asPrettyString)
                    .collect(Collectors.toList());

            builder.append(Component.text(" - ", NamedTextColor.DARK_AQUA))
                    .append(Component.join(JoinConfiguration.separator(Component.space()), argUsages))
                    .build();
        }

        sender.sendMessage(builder.build());
    }
Predicate to test if the argument length given is invalid
common/src/main/java/me/lucko/luckperms/common/command/abstraction/GenericChildCommand.java