sert_true(MathMLFeatureDetection.has_mspace());
              assert_equals(x.bottom, y.top);
          }, `baseline alignment inside ${tag}`);
      });
      done();
  }
</script>
</head>
<body>
  <div id="log"></div>
  <p>
    <math><mrow><mspace id="aboveMrow" width="10px" height="30px" style="background: purple"></mspace><mspace id="belowMrow" width="10px" depth="30px" style="background: blue"></mspace></mrow></math>
    <math><msqrt><mspace id="aboveSqrt" width="10px" height="30px" style="background: 