Boolean newOpen = this.arg(0, ARBoolean.get(), !usenderFaction.isOpen());
if (newOpen == null) return;
// Event
FactionsEventOpenChange event = new FactionsEventOpenChange(sender, usenderFaction, newOpen);
event.run();
if (event.isCancelled()) return;
newOpen = event.isNewOpen();
// Apply
usenderFaction.setOpen(newOpen);