This is the 1st followup of [!56242 (merged)]
Since in that one we finally avoid creating everything
Now we are able to actually "manipulate" things without
const_cast for a change ...
One has to look only on the following commit and any commits after that one until the previous MR is merged (ATLAS-EGamma/athena@cb90a633)
The true purpose / magic is the TrackingVolumeManipulator
that now becomes
There are one "syntactical" question I had on combining
shared_ptr etc ...
with whom I discussed them.
A mock perhaps easier to parse .
[https://godbolt.org/z/MdzEjaYMG] (scroll around line 500)