 <p>I figured out why I was getting the error. In the list that was being returned, sometimes <code>id</code> was appearing before <code>high_score</code>, i.e. I was getting <code>"id": 10, "high_score": 180</code>, which is why the test ran OK. But at other times <code>high_score</code> was appearing before <code>id</code>, i.e. it was <code>"high_score": 180, "id": 10</code>, which is why the test was failing.</p>