while (enumerator.MoveNext())
{
    SurvivorDef survivor = new SurvivorDef();
    survivor = enumerator.Current;
    ViewablesCatalog.Node survivorEntryNode = new ViewablesCatalog.Node(survivor.survivorIndex.ToString(), false, node);
    survivorEntryNode.shouldShowUnviewed = ((UserProfile userProfile) => !userProfile.HasViewedViewable(survivorEntryNode.fullName) && userProfile.HasSurvivorUnlocked(survivor.survivorIndex) && !string.IsNullOrEmpty(survivor.unlockableName));
}