public boolean unsubscribe(Permissible permissible, String permission) {
        if (permissible instanceof Player) {
            return false; // ignore calls for players
        }

        Set<String> perms = this.subscriptions.get(permissible);

        if (perms == null) {
            return false;
        }

        return perms.remove(permission);
    }
A replacement map for the 'permSubs' instance in Bukkit's SimplePluginManager.

This instance allows LuckPerms to intercept calls to
{@link PluginManager#subscribeToPermission(String, Permissible)},
{@link PluginManager#unsubscribeFromPermission(String, Permissible)} and
{@link PluginManager#getPermissionSubscriptions(String)}.

Bukkit for some reason sometimes uses subscription status to determine whether
a permissible has a given node, instead of checking directly with
{@link Permissible#hasPermission(String)}.

{@link org.bukkit.Server#broadcast(String, String)} is a good example of this.

In order to implement predicable Bukkit behaviour, LP has two options:
1) register subscriptions for all players as normal, or
2) inject it's own map instance to proxy calls to {@link PluginManager#getPermissionSubscriptions(String)} back to LuckPerms.

This class implements option 2 above. It is preferred because it is faster & uses less memory

Injected by {@link InjectorSubscriptionMap}.
bukkit/src/main/java/me/lucko/luckperms/bukkit/inject/server/LuckPermsSubscriptionMap.java