dler.
future.catchError((e) { throw "is never reached"; });
}
</code></pre>
<p>Note that errors cannot enter a child zone with a different error handler
either:</p>
<pre class="language-dart"><code>import 'dart:async';

main() {
runZoned(() {
// The following asynchronous error is *not* caught by the `catchError`
// in the nested zone, since errors are not to cross zone boundaries
// with different error handlers.
// Instead the error is handled by the current error handler,
// printing "Caught by outer zon