rs on this stream are considered unhandled,
and will be passed to the current <a href="../../dart-async/Zone-class.html">Zone</a>'s error handler.
By default unhandled async errors are treated
as if they were uncaught top-level errors.</p>
<p>If this stream closes and sends a done event, the <code>onDone</code> handler is
called. If <code>onDone</code> is <code>null</code>, nothing happens.</p>
<p>If <code>cancelOnError</code> is true, the subscription is automatically canceled
when the first error event is