Fold a range, replacing it with the text "??"
var range = cm.markText({line: 4, ch: 2}, {line: 8, ch: 1}, {
  replacedWith: document.createTextNode("??"),
  // Auto-unfold when cursor moves into the range
  clearOnEnter: true
});
// Get notified when auto-unfolding
CodeMirror.on(range, "clear", function() {
  console.log("boom");
});
</pre>
</section>
<section id=lineclass>
  <h2>Line CSS classes</h2>

<p>The <code>setLineClass</code> method has been replaced
by <a href="manual.html#addLineClass"><code>addL