Function take 

pub fn take() -> StorageState

Take the current storage, leaving a fresh (empty) profile in its place — reset, but the profile it replaces comes back to the caller instead of being dropped. A nested run (a candidate page tier compared against the reference) takes the caller’s storage before writing its own, and restores it when it is done, so the caller’s own storage survives the comparison instead of leaking into — or out of — the candidate’s run.