A common protocol structure is to have a header containing a length field, followed by data of length bytes, followed by additional protocol fields such as a CRC. If the length field is variable, the position of subsequent URH-specified protocol fields defined by fixed position will not be in the correct location.

I do not know the best way to address this, but quick and easy way to support

unicode_literals was necessary pre-Python 2.6; absolute_import pre-2.5.

It's especially not necessary on Py3.

Hence in the sence of cleaning up the source tree, deletion of all from __future__ import something from the python files is desirable. This should ideally not happen manually, but with a script, or command line: we need to do that on master, but it might also be desirable to