title: NSubstitute - Make member return result of a lambda invocation
body: <p>We all know the standard of way of specifying a return value for a substitute:</p>
  
  <pre><code>mySubstitute.Method().Returns(myValue);
  </code></pre>
  
  <p>I need myValue to be computed at the point of each invocation though, not just once. Is this possible?</p>
  
  <p>Example:</p>
  
  <pre><code>mySubstitute.Method().Returns(() =&gt; ComputeValueBasedOnSystemClockAndTheWeather());
  </code></pre>
  
  <p>Of course this won't compile, since <code>Method()</code> doesn't really return a lambda.</p>