title: What is a no-op class?
body: <p>I just learned about the Template Method pattern in <a href="https://stackoverflow.com/questions/2945147/make-sure-base-method-gets-called-in-c/2945171#2945171">this answer</a> to a question about ensuring that methods in base classes are always called by child classes.</p>
  
  <p>Part of the answer talks about base classes vs no-op classes:</p>
  
  <blockquote>
    <p>(The decision about whether to make it
    a no-op or abstract is usually fairly
    obvious - does the base class make
    sense on its own, as a concrete
    class?)</p>
  </blockquote>
  
  <p>What is a no-op class?</p>