support request: old references get deleted

[Egon Willighagen]

I am trying to write a bot to add information about metabolites. I got pretty far, resulting in a typical diff on Wikidata like here: https://www.wikidata.org/w/index.php?title=Q26690136&type=revision&diff=370019726&oldid=370019096

To me, it is a problem that it removed old references, like 'determination method' 'Bioclipse'. I did figure out how to get it to update 'stated in' 'WikiPathways', but I cannot get the bot to not remove the P459 references.

Help is very much appreciated. I had a look at the PBB core bot, and tried various changes in my code and in the PBB code (the part that handles references)... but I just cannot get it to work.

The code of my bot is found in this branch: https://bitbucket.org/egonw/wikidatabots/branch/feature/metabolites