title: Is it possible to add a method to an EXISTING class at runtime? why or why not?
body: <p>I would imagine this might use Reflection.Emit,</p>
  
  <p>but <a href="https://stackoverflow.com/questions/3551452/how-to-create-a-method-at-runtime-using-reflection-emit">a similar question on SO</a> only answers how to create a class/method dynamically, not how to update an existing class.</p>
  
  <p>In a similar vein, is it possible to delete methods / classes at runtime?  If so, I suppose one could just delete the class, and add it back with its old methods plus the new one.</p>
  
  <p>Thanks in advance.</p>
  
  <p>P.S.  I don't have an intended use for this, it is merely a matter of curiosity.</p>