example src/network/examples/main-packet-header.cc no longer works as expected; it no longer prints out the header (MyHeader::Print()).

I found this in packet.cc, line 429:
#if 0
  // The code below will work only if headers and trailers
  // define the right attributes which is not the case for
  // now. So, as a temporary measure, we use the 
  // headers' and trailers' Print method as shown above.

...

So at some point (which I could not easily find but it dates back to prior to ns-3.4) this was disabled.

Suggested next steps?