Yeah I got home and found it. It's not obvious but any string type that doesn't end in " Nodes" is mapped as a single node model.
static bool HasSingleNode(const std::string& StrType)
{
static std::string Nodes(" Nodes");
if (Nodes.size() > StrType.size()) return false;
return !std::equal(Nodes.rbegin(), Nodes.rend(), StrType.rbegin());
}