public string Wkt {get;}

// Create from wkid
HVDatumTransformation hv110018 = HVDatumTransformation.Create(110018);
int wkid = hv110018.Wkid;
bool isForward = hv110018.IsForward;    // isForward = true
string name = hv110018.Name;            // Name = WGS_1984_To_WGS_1984_EGM2008_1x1_Height

// Create from wkt
string wkt = hv110018.Wkt;
HVDatumTransformation hv110018FromWkt = HVDatumTransformation.Create(wkt);

// Get the inverse
HVDatumTransformation hv110018Inverse = 
   hv110018.GetInverse() as HVDatumTransformation;
// hv110018Inverse.IsForward = false