pub trait MutLockTrait<T: MutLockGuardTrait, E: Error> {
// Required method
fn lock_mut(&mut self) -> Result<MutLockGuard<T>, E>;
}pub trait MutLockTrait<T: MutLockGuardTrait, E: Error> {
// Required method
fn lock_mut(&mut self) -> Result<MutLockGuard<T>, E>;
}