that's that
成語所屬單字that
that's that — 慣用語
1. used to show that a decision has been made and will not be discussed or changed.
1.慣用語
釋義
就這樣決定了；就這麼辦
used to show that a decision has been made and will not be discussed or changed.
例句
I am not lending you any more money, and that's that.
The teacher said we have to finish this by Friday, and that's that.