@Nonnull
    @Override
    public BossBar newBossBar() {
        return new BukkitBossBar(this.server.createBossBar("null", convertColor(BossBarColor.defaultColor()), convertStyle(BossBarStyle.defaultStyle())));
    }
Implementation of {@link BossBarFactory} using Bukkit.
helper/src/main/java/me/lucko/helper/bossbar/BukkitBossBarFactory.java