message: silence rng deprecation warning
diff: +use rand::seq::SliceRandom;
  use rand::Rng;
  use salsa::Database;
  use salsa::ParallelDatabase;
  @@ -82,7 +83,7 @@ enum ReadOp {
  impl rand::distributions::Distribution<Query> for rand::distributions::Standard {
  fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> Query {
  - *rng.choose(&[Query::A, Query::B, Query::C]).unwrap()
  + *[Query::A, Query::B, Query::C].choose(rng).unwrap()
  }
  }
  