1use crate::*; 2 3pub struct Null; 4impl App for Null { 5 type Op = (); 6 type Res = (); 7 fn replica_upcall(&mut self, _op_num: OpNum, _op: Self::Op) -> Self::Res {} 8 fn unlogged_upcall(&mut self, _op: Self::Op) -> Self::Res {} 9}