usage of $VERSIONGUID, $FINGERPRINTGUID

[chrmangold]

Hi!

I want to know if the following is an intended behaviour of ezdxf package.

# open a simple dxf file (eg. acad_table_simple.dxf)
doc = ezdxf.readfile(dxf_path)

# then print special header variables
print(doc.header['$FINGERPRINTGUID'])
print(doc.header['$VERSIONGUID'])

valid uuids will be printed out.
But - one can find the values in the dxf file. The printed uuids are not identical to the ones in the dxf file

And - each time I restart this snippet I get different uuids printed out.

For me it seems like an unwanted situation, but I am not quite sure about that.

I need to be able to identify one drawing out of some attributes.
So what is the best way to achieve this goal?

Thanks for any suggestions,

Chris