Setting up complex values for `Deno.bench` function runs

const a = <T>(arr: T[], ...items:T[]): T[] => {};
const b = <T>(arr: T[], ...items:T[]): T[] => {};

const getSample = () => {
  const sample:number[] = [];
  for (let i = 0; i < 1e6; i++) sample.push(i);
  return sample;
};

Deno.bench('a', () => {
  const data = getSample();
  a(data, -1);
});

Deno.bench('b', () => {
  const data = getSample();
  b(data, -1);
});

Deno.bench({
  name: 'a',
  prerun: () => getSample(),
  fn(data) { // `data` === `ReturnType<typeof prerun>`
    a(data, -1);
  }
});