Can I undo NSubstitute's Returns() substitution without recreating the mock?
<p>Using NSubstitute, I can do this:</p>

<pre><code>mock.doStuff().Returns(foo);
</code></pre>

<p>But for a large test fixture, this isn't appropriate in every test.</p>

<p>So can I "undo" that <code>Returns()</code> substitution, or must I recreate the mock before each test? (which is slooooow...)</p>