System.Net.NetworkInformation.Ping.Dispose C# (CSharp) Method

        protected override void Dispose(bool disposing) { }
        protected void OnPingCompleted(System.Net.NetworkInformation.PingCompletedEventArgs e) { }

 public static void Trace(IPAddress destination, Func<IPAddress, TracertNode, bool> callback)
 {
     if (destination == null)
     {
         throw new ArgumentNullException("destination");
     }
     else
     {
         if (callback == null)
         {
             throw new ArgumentNullException("callback");
         }
         else
         {
             var syncroot = new object();
             var buffer = new byte[INT_BufferSize];
             var options = new PingOptions(1, true);
             var ping = new Ping();
             ping.PingCompleted += (sender, e) =>
             {
                 var address = e.Reply.Address;
                 var status = e.Reply.Status;
                 back:
                 var done = !callback.Invoke(destination, new TracertNode(address, status, e.Reply.Options.Ttl)) || address.Equals(destination);
                 if (done)
                 {
                     try
                     {
                         if (ping != null)
                         {
                             ping.Dispose();
                         }
                     }
                     finally
                     {
                         ping = null;
                     }
                 }
                 else
                 {
                     lock (syncroot)
                     {
                         if (ping == null)
                         {
                             address = destination;
                             status = IPStatus.Unknown;
                             goto back;
                         }
                         else
                         {
                             options.Ttl++;
                             ping.SendAsync(destination, INT_TimeoutMilliseconds, buffer, options, null);
                         }
                     }
                 }
             };
             ping.SendAsync(destination, INT_TimeoutMilliseconds, buffer, options, null);
         }
     }
 }