Function request_counts_subtree 

pub fn request_counts_subtree(
    totals: &[AtomicU64; 18],
    windows: &[Mutex<RequestRateWindows>; 18],
    now: TimeMillis,
) -> Value

Build the requests subtree: one object per [PayloadRequestKind] variant, keyed by its Display name, holding the all-time total plus the decaying per_hour / per_day / per_month rate estimates evaluated at now.

Total reads use Ordering::Relaxed — counters are advisory metrics, not synchronisation primitives, and the snapshot doesn’t need to be coherent across kinds.