```ts
export function heldDown(value: number, ceiling: number): number {
  return value > ceiling ? ceiling : value;
}

/** Every value of a store brought down to a ceiling. */
export function limitMap(
  store: Record<string, number>,
  ceiling: number,
): Record<string, number> {
  const out: Record<string, number> = {};
  for (const key of Object.keys(store)) {
    out[key] = heldDown(store[key], ceiling);
  }
  return out;
}
```