text: import test from 'ava';
  
  import challenge, { readNos } from '.';
  
  // https://www.reddit.com/4bwibm/
  test('Challenge #259 [Hard] Operator number system', t => {
    t.true(readNos('10020') === 21);
    const res = challenge(7);
  
    t.true(res[21] === '10020');
  });
  