a of this stream in a <a href="dart-core/Set-class.html">Set</a>.</p>
<p>Creates a <code>Set&lt;T&gt;</code> and adds all elements of this stream to the set.
in the order they arrive.
When this stream ends, the returned future is completed with that set.</p>
<p>The returned set is the same type as returned by <code>new Set&lt;T&gt;()</code>.
If another type of set is needed, either use <a href="dart-async/Stream/forEach.html">forEach</a> to add each
element to the set, or use
<code>toList().then((list) =&gt