title: How can I replace an already declared stub call with a different stub call?
body: <p>If I have a Rhino Mock object that has already has a stub call declared on it like this:</p>
  
  <pre><code>mockEmploymentService.Stub(x =&gt; x.GetEmployment(999)).Return(employment);
  </code></pre>
  
  <p>Is there anyway I can remove this call to replace it with something different e.g.:</p>
  
  <pre><code>mockEmploymentService.Stub(x =&gt; x.GetEmployment(999)).Return(null);
  </code></pre>
  
  <p>The reason I ask is that I want to set up some generic mocks to be used in multiple unit tests and then allow each unit test to tailor the calls where necessary.</p>