title: C#-style event accessors for CLI events in F#
body: <p>I am exposing an event from F# to C# like this:</p>
  
  <pre><code>let event = new DelegateEvent&lt;EventHandler&gt;()
  member x.Ping() = event.Trigger([| x; EventArgs.Empty |])
  [&lt;CLIEvent&gt;]
  member x.PingEvent = event.Publish
  </code></pre>
  
  <p>But I'd like some code to run whenever handlers are added or removed. I think this can be done in C# like this:</p>
  
  <pre><code>public event EventHandler PingEvent
  {
      add 
      {
          //do something
      }
      remove
      {
          //do something
      }
  }
  </code></pre>
  
  <p>How do I write the above in F#?</p>