in usefulnes

// Game of Key-owns
export default function (data = {}) {
  // your code starts here
  let keys = Object.values(data)[0]; // keys [a, b, c]
  let newObj = {};


  for (const keyToCheck of keys) {
    let key = keyToCheck.toString();
    if((key in data.first) && (key in data.second)) { // first has a and second has a

      newObj[key] = [data.first[key], data.second[key]];

    } else if ((key in data.first) && !(key in data.second)){

      newObj[key] = data.first[key];

    } else if (!(key in data.first) && (key in data.second)){

      newObj[key] = data.second[key];

    } else {
      newObj[key] = null;
    }
  }


  return newObj
  // your code ends here
}