as flex-start. -->
<div data-expected-height="30" class="flexbox horizontal" style="-webkit-align-content: space-between; height: 30px">
  <div data-offset-x="0" data-offset-y="0" data-expected-height="20"></div>
  <div data-offset-x="100" data-offset-y="0" data-expected-height="20"></div>
  <div data-offset-x="0" data-offset-y="20" data-expected-height="20"></div>
  <div data-offset-x="0" data-offset-y="40" data-expected-height="20"></div>
</div>

<!-- If we overflow, we should true center. -->
<div data-e