if (notifying) {
            pendingNodes.put(node, PendingState.ADD);
            return;
        }

        doAdd(node);
        flush();
    }

    public void nodeDiscovered(ModelNodeInternal node) {
        if (notifying) {
            if (!pendingNodes.containsKey(node)) {
                pendingNodes.put(node, PendingState.NOTIFY);
            }
            return;
        }

    }

    @Override
    public PendingState maybeAddAsPendingDependency(NodeState node, DependencyState dependencyState) {
        ModuleIdentifier key = dependencyState.getModuleIdentifier();
        boolean isConstraint = dependencyState.getDependency().isConstraint();
        if (!isConstraint) {
            if (markNotPending(key)) {
                return PendingState.NOT_PENDING_ACTIVATING;
            } else {

    enum PendingState {
        PENDING(true),
        NOT_PENDING(false),
        NOT_PENDING_ACTIVATING(false);

        private final boolean pending;

        PendingState(boolean pending) {
            this.pending = pending;
        }

        boolean isPending() {
            return this.pending;
        }
    }