/*
     ============================================================================
     MANAGING NOTIFICATIONS
     ============================================================================     
     */
    private class BloodBankNote extends BloodBank {

        protected int notifier;

        BloodBankNote(int iD, BloodBank bB) {
            super(bB, bB.getCapacity());
            this.increaseBloodLoad(bB.getBloodLoad());
            this.notifier = iD;
        }

        int getNotifier() {
            return notifier;
        }

        void setNotifier(int iD) {
            notifier = iD;
        }

    } // end BloodBankNote class 

    private class DonorNote extends Donor {

        protected int notifier = 0;

        DonorNote(int iD, Donor d) {
            super(d);
            this.notifier = iD;
        }

        int getNotifier() {
            return notifier;
        }

        void setNotifier(int iD) {
            notifier = iD;
        }
    } // end DonorNote class

heres a comment

MANAGING NOTIFICATIONS

Java