fn abort(&mut self);
fn assume(&mut self, val: Self::Value);
fn expect(&mut self, cond: Self::Value, expected: bool) -> Self::Value;
+ fn sideeffect(&mut self);
/// Trait method used to inject `va_start` on the "spoofed" `VaListImpl` in
/// Rust defined C-variadic functions.
fn va_start(&mut self, val: Self::Value) -> Self::Value;