title: EventHandler type with no event args
body: <p>When we want to pass data to an event subscriber, we use EventArgs (or CustomEventArgs) for this.</p>
  
  <p>.Net provides a build in type EventHandler that uses as a parameter an instance of EventArgs class that is build in as well.</p>
  
  <p>What about cases, when I need to notify a subscriber that some action is over, for example search is over? I don't want to even use EventArgs, that won't contain anything. </p>
  
  <p>Is there a build in type for signaling another class, without the need to use empty EventArgs?</p>