Function json_gt 

pub fn json_gt(a: &Value, b: &Value) -> bool

Total-order “greater than” over JSON values, using the same comparison filter_incremental applies to replication keys (numbers numerically, strings lexicographically — so RFC3339 timestamps order correctly). Public so callers bounding a replay window (e.g. faucet backfill --to-bookmark) compare exactly like the incremental filter does.