Constant KEEP 

const KEEP: Duration;

How long an entry is kept after the subject that filled it.

Measured on the clock the subjects themselves carry — Universal::now, the instant the caller is judging at — so this holds wherever this crate runs, the browser policy checker included.

A write asks every statement about one subject in one burst, so the reuse an entry exists for happens within microseconds of it being filled. Seconds rather than milliseconds because a write descheduled partway through its statements should still find its own entry; anything longer is a copy of an account’s record held for no further gain.