void viewUpdated(boolean invalidateCache) {
   if (bill != null) {
     if (invalidateCache) bill = repository.find(bill.getUuid());
     if (editView != null) {
       editView.setTitle(R.string.edit_bill_title);
     } else {
       String title = view.getContext().getString(R.string.bill);
       view.setTitle(title.concat(" ").concat(bill.getName()));
     }
     view.showBill(bill);
     initDate = bill.getInitDate();
     if (editView != null) editView.onInitDateChanged(initDate);
     endDate = bill.getEndDate();
     if (editView != null) editView.onEndDateChanged(endDate);
   } else {
     if (editView != null) editView.setTitle(R.string.new_bill_title);
   }
 }
 String getUuid() {
   return bill != null ? bill.getUuid() : null;
 }