What is G4VNestedParameterisation::GetMaterial(int) supposed to do?

I cannot find documentation on what G4VNestedParameterisation::GetMaterial(int) is supposed to do, and for that matter G4VNestedParameterisation::GetNumberOfMaterials().

Looking at the code, it seems that the loop

for(int i=0;i<param.GetNumberOfMaterials();++i){
    param.GetMaterial(i);
}

should go through all the materials used by the G4VNestedParameterisation. Is this correct?