It's broke

    public SearchResult search(String initConfig, int modeFlag) {
        int numPoppedStates = 0;
        char[] possibleMoves = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H'};

        // Step 1
        PriorityQueue<State> open = new PriorityQueue<State>(11, State.comparator);
        HashMap<String, Integer> realCosts = new HashMap<String, Integer>();
        State initial = new State(initConfig, 0, getHeuristicCost(initConfig, modeFlag), "");
        open.add(initial);

        // Step 2
        while (!open.isEmpty()) {
            // Step 3
            State state = open.poll();
            numPoppedStates ++;

            // Step 4, 5, 6
            if (checkGoal(state.config)) {
                return new SearchResult(state.config, state.opSequence, numPoppedStates);
            }

            // Step 7, 8
            for (char moveChoice : possibleMoves) {
                String childConfig = move(state.config, moveChoice);
                State childState = new State(childConfig, state.realCost + 1,
                        getHeuristicCost(childConfig, modeFlag), state.opSequence + moveChoice);

                // Step 9, 10, 11
                if (!realCosts.containsKey(childState.config)) {
                    realCosts.put(childState.config, childState.realCost);
                    open.add(childState);
                } else {
                    // Step 13
                    if (childState.realCost < realCosts.get(childState.config)) {
                        // Step 15, 16, 17, 18
                        realCosts.put(childState.config, childState.realCost);
                        open.remove(childState);
                        open.add(childState);
                    }
                }
            }
        }

        return null;
    }