I want to change the wireshark code. But I can't figure it out

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I want to add columns with data about countries ("country A" and"country B") in the "wireshark-conversations"window. It's like the "wireshark-endpoints" window has a "Country" column when MaxMind DB is connected. I added columns, but I can't fill them in. I can't find the necessary information about the code structure. Maybe there are some sources other than developer guide and Readme.*. Maybe you can contact people who can help with this. Thanks