Function spawn_kernel_and_run_sync 

pub fn spawn_kernel_and_run_sync<F, R>(callback: F) -> impl Future<Output = R>
where
    F: FnOnce(&mut Locked<Unlocked>, &mut CurrentTask) -> R + Send + Sync + 'static,
    R: Send + Sync + 'static,

Create a Kernel object and run the given synchronous callback in the init process for that kernel.

This function is useful if you want to test code that requires a CurrentTask because your callback is called with the init process as the CurrentTask.