private void tick() {
        // remove listeners where the sender is no longer valid
        this.listeners.values().removeIf(l -> !l.getNotifiedSender().isValid());

        // handle all events in the queue
        flush();

        // update listening state
        this.listening = !this.listeners.isEmpty();
    }
Removes a listener for a given player

@param sender the sender
@return the existing listener, if one was actually registered
common/src/main/java/me/lucko/luckperms/common/verbose/VerboseHandler.java