> , I wonder if we could not change directly records instead.

Updating to this: 

```js
if (records !== null) {
  /*
    record[0] is the threadId or null key
    record[1] is the array of draft objects associated
               with that threadId or null key

    Replace each plain object in record[1] with a
    real draft object.

    Once ES6 syntax is allowed,
    replace the map operations below with the following line:
    record[1].map(draft => new Draft(draft));
  */
  rlength = records.length;

  for (var i = 0; i < rlength; i++) {
    drafts = records[i][1];
    dlength = drafts.length;

    for (var j = 0; j < dlength; j++) {
      drafts[j] = new Draft(drafts[j]);
    }
  }
}
```