between zones with
different error handlers.</p>
<p>Example:</p>
<pre class="language-dart"><code>import 'dart:async';

main() {
var future;
runZoned(() {
// The asynchronous error is caught by the custom zone which prints
// 'asynchronous error'.
future = new Future.error("asynchronous error");
}, onError: (e) { print(e); });  // Creates a zone with an error handler.
// The following `catchError` handler is never invoked, because the
// custom zone created by the call to `runZoned` provides an
// error han