[gnulib-tool-py] from func_import to GNULibImport class

[Dmitriy Selyutin]

I'm now working on GNULibImport class, which is derived from GNULibMode class and is used to provide methods for --import, --add-import, --remove-import, --update modes (I think it is a good idea to combine it all into one class because the most part of actions are the same for all these options). However it is difficult to understand what code from lines 4141-4247 (as it appears in the latest version of gnulib-tool) does (here script defines my_sed_traces variable). Could someone help me with parsing? Just explain me what this code does or what I need to do. As I understand it reads data from "$destdir"/$m4base/gnulib-cache.m4. As I understand I have to use re module in combination with open("gnulib-cache.m4").read(), but may be there is a better way than translating to regex again. Thanks!