How does benchmark_rx.py use the header?

GNU Radio
1

I`m running the benchmark_xx.py.

In benchmark_rx.py, the function unmake_packet uses payload_with_crc
instead of a packet containing preamble, accesscode and header.

Then, header is used at correlator or framer?

But I couldn`t find any code line about using header.

correlator and framer just contain return code like this.
return _gnuradio_core_general.framer_sink_1(*args, **kwargs)

How does benchmark_rx.py use the header?
Where can I find the code about using the header?

ps. Is it correct packet structure??
accesscode : header : payload_with_crc : ‘\x55’