title: Using separate data sets for the same fixture
body: <p>I have a shell that sends out emails updating a person on their account status.  In order to compile the list of people who need to receive this email today, I have a method that executes the appropriate <code>find('all')</code> query and returns the list of recipients.  I want to unit test this method to make sure this list is being generated correctly.</p>
  
  <p>However, now I have two unit tests depending on my Person fixture - my Person model's test, and this shell test.  The extra clutter from the Person model test makes it awkward to prepare a data set focused on my shell test.  The tests are complected - if I change the data set for one, I might break the other.</p>
  
  <p>Can I easily define separate data sets for the same fixture depending on the context?  Can I create separate fixtures for separate tests?  How?</p>