e</code>, there are no further elements
and <a href="dart-core/RuneIterator/current.html">current</a> should not be used any more.</p>
<p>It is safe to call <a href="dart-core/RuneIterator/moveNext.html">moveNext</a> after it has already returned <code>false</code>,
but it must keep returning <code>false</code> and not have any other effect.</p>
<p>A call to <code>moveNext</code> may throw for various reasons,
including a concurrent change to an underlying collection.
If that happens, the iterator may be in