int index; if ((index = refillRequisitions.indexOf(task)) != -1) { refillRequisitions.set(index, null); }
for (int i = 0; i < refillRequisitions.size(); i++) { ArrayList refills = (ArrayList) refillRequisitions.get(i); if(refills != null) { if(refills.remove(task)){ if(refills.size() < 1) { refillRequisitions.set(i, null); } } } }
    public void removeRefillRequisition(Task task) {        int index;        if ((index = refillRequisitions.indexOf(task)) != -1) {            refillRequisitions.set(index, null);        }    }