Function assert_isolation 

pub fn assert_isolation(
    reports: &[WorkerReport],
    expected: &BTreeSet<usize>,
) -> AssertResult

Check that workers only ran on CPUs in expected.

Any worker that used a CPU outside the expected set produces a failure with the unexpected CPU IDs listed.

let expected: BTreeSet<usize> = [0, 1, 2].into_iter().collect();
assert!(assert_isolation(&[report], &expected).is_pass());