-- Runtime residual check: `get` on a `map` with a key that isn't present
-- traps KEY (docs/plan/oop-vm/08-builtin-surface.md's `get` row: "a
-- missing key traps KEY"). Unprovable at compile time -- the key is a
-- runtime `Text` value -- so it traps rather than failing to compile:
-- the hybrid boundary's runtime half.
class Catalog {
  prices: map<Text, Int>
}

fn main() {
  let c = Catalog { prices: map_new() }
  set(c.prices, "mug", 499)
  print_int(c.prices["shirt"])
}