 data-expected-height="45">
        <p>xx xxx</p>
        <p>xx</p>
      </div>
    </div>
    <br>

    <!-- Row 2: Specified main-size, cross-size, or flex-basis: -->
    <div class="flexbox">
      <div style="width: 30px"
           data-expected-width="30" data-expected-height="45">
        <p>xx xxx</p>
        <p>xx</p>
      </div>
    </div>
    <div class="flexbox">
      <div style="height: 30px"
           data-expected-width="70" data-expected-height="30">
        <p>xx xxx</p>
        <p>xx</