How to define parallel geometric materials

Hi Geant4ers:
Hello, experts. Recently I have been using DICOM sample modeling to test my radioactive seeds.I used parallel geometry to place the radioactive seeds I defined, but I had a bit of a problem with the material definition.

In the manual I came across this passage:Volumes in a parallel world may have materials. Such materials overwrite the materials defined in the mass. Volumes in a parallel world may have materials geometry if the “layered mass geometry” switch of the G4ParallelWorldProcess constructor is set.

But in the extended example GB06 I found that the example used G4Material to define the material and use this material in the parallel geometry construction.

So I’m a little confused as to whether I can also define the material and use it directly in parallel geometry definitions as in this example, or whether I should define the material strictly according to the manual.

And here I also want to ask the experts how to define the material of parallel geometry.
Thank you very much for your guidance and advice. I wish you a happy life.