title: Why don't I see the += operator overloaded on System.Delegate?
body: <p>I see the equality comparison operators <code>==</code> and <code>!=</code> overloaded on <code>System.Delegate</code> and <code>MulticastDelegate</code> but not the <code>+=</code> and <code>-=</code> operators.</p>
  
  <p>Then how do the increment assign and decrement assign operators work on delegate instances?</p>