public void handleDisconnect(UUID uniqueId) {
        // Register with the housekeeper, so the User's instance will stick
        // around for a bit after they disconnect
        this.plugin.getUserManager().getHouseKeeper().registerUsage(uniqueId);

        // force a clear of transient nodes
        this.plugin.getBootstrap().getScheduler().executeAsync(() -> {
            User user = this.plugin.getUserManager().getIfLoaded(uniqueId);
            if (user != null) {
                user.clearNodes(DataType.TRANSIENT, null, false);
            }
        });
    }
Gets the unique players which have connected to the server since it started.

@return the unique connections
common/src/main/java/me/lucko/luckperms/common/plugin/util/AbstractConnectionListener.java