<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html lang="en">
<head>
<style>
.container { width: 50px; border: 0px solid blue; background: green; }
.collapsedThrough { width: 200px; border: 0px solid blue; margin-top: 100px; }
</style>
</head>
<body>
<div class=container style="border-top-width: 1px">
  <div class=collapsedThrough></div>
</div>
<div class=container style="border-top-width: 1px; border-bottom-width: 1px">
  <div class=collapsedThrough></div>
</div>
</body>
</html>