than an error.
The thrown object can choose to implement <a href="dart-core/Exception-class.html">Exception</a>
to document that it represents an exceptional, but not erroneous, occurrence,
but it has no other effect than documentation.</p>
<p>All non-<code>null</code> values can be thrown in Dart.
Objects extending <code>Error</code> are handled specially:
The first time they are thrown,
the stack trace at the throw point is recorded
and stored in the error object.
It can be retrieved using the <a href="da