/// <summary>
 /// Send a message to a process
 /// </summary>
 /// <param name="pid">Process ID to send to</param>
 /// <param name="message">Message to send</param>
 /// <param name="sender">Optional sender override.  The sender is handled automatically if you do not provide one.</param>
 public static Unit tell <T>(ProcessId pid, T message, ProcessId sender = default(ProcessId)) =>
 message is UserControlMessage
         ? ActorContext.TellUserControl(pid, message as UserControlMessage)
         : ActorContext.Tell(pid, message, sender);