private void removeAllBuffs(Set<Buff> buffs) {
		if (buffs != null) {
			// remove buffs with array loop to avoid concurrentModification exception
			// which will be thrown by the 'removeBuff' method otherwise
			Buff[] array = buffs.toArray(new Buff[buffs.size()]);
			for (int i = 0; i < array.length; ++i) {
				removeBuff(array[i].getTarget(), array[i]);
			}
		}
	}