this.wb = (DefaultWriteBarrier) heapManager.getWriteBarrier();
this.writeBarrier = (DefaultWriteBarrier) heapManager.getWriteBarrier();
    public GCManager(DefaultHeapManager heapManager, VmArchitecture arch,            VmStatics statics) {        this.debug = Vm.getVm().isDebugMode();        this.heapManager = heapManager;        this.wb = (DefaultWriteBarrier) heapManager.getWriteBarrier();        this.helper = heapManager.getHelper();        this.markStack = new GCStack();        this.markVisitor = new GCMarkVisitor(heapManager, arch, markStack);        this.setWhiteVisitor = new GCSetWhiteVisitor(heapManager);        this.verifyVisitor = new GCVerifyVisitor(heapManager, arch);        this.stats = new GCStatistics();        this.statics = statics;        this.resolver = new Unsafe.UnsafeObjectResolver();    }