Based on a question regarding pillaging I present the following situation and propose the subsequent questions.

Situation: A regent starts with 3 GBs, collects taxes at the start of the Domain Turn. During the first two Domain Actions the regent spends all of the collected funds. During the third domain action three of the regent's five provinces are invaded and occupied. These three provinces originally generated 12 GBs in tax income. According to the rules of conquest and occupation: ''A province under enemy control generates no taxation, collection, or regency for the province ruler.''

Questions:
-Does occupation take effect in the current Domain Turn?
-If the occupation takes place in the current Domain turn,
does this mean that all or some of the 12 GBs the provinces would have generated that domain turn are voided?
-How can the collected taxes be voided if they are already spent?