Where is the code in HOI4 that defines how an AI decides on events (e.g. "Split Czechoslovakia")?

I cannot find the code, that defines how an AI decides on an event that is triggered by another countries focus. In particular I cannot find how Germany decides whether or not to "Split Czechoslovakia", after Romania finished this focus?

In the file "Hearts of Iron IV/common/national_focus/romania.txt" I found the following code:

focus = {
    id = ROM_split_czechoslovakia

    [... some other code ...]

    completion_reward = {
        GER = { country_event = DOD_romania.110 }
    }
}

But I could not find where "DOD_romania.110" is defined. Can anybody help me out?

I ran several different games and Germany always denied the Split - even if I Increased Relations to 100. This is really annoying because shortly afterwards Germany will Demand Sudentenland and in non-historic might have to attack Czechoslovakia - and now I am asked to honor my Guarantee of Czechoslovakia to fight Germany and Italy in 1938 with Czechoslovakia as my only ally and being the only major on my side (good luck). So I would really like to know how the AI decides this.