private void delete(PQueueEntry a) { if (a.getPrev() == null && a.getNext() == null) { head = null; } else { if (a.getPrev() == null) { a.getNext().setPrev(null); head = a.getNext(); } else { a.getPrev().setNext(a.getNext()); } if (a.getNext() == null) { a.getPrev().setNext(null); } else { a.getNext().setPrev(a.getPrev()); } } size--; }