houio::HouGeo::Topology has missing information

[nyue]

Using the Topology reference object returned by the houio::HouGeo pointer via the method getTopology(), I found the object lacks information to build a topology for mesh export

I noticed there are different Topology classes, one from HouGeoAdapter another one from HouTopology

Basically, I need to get the one from HouTopology as it has additional information indexBuffer whereas the other Topology does not have that.

Why are they different ?