/// <summary>
/// This method causes the communication listener to close. Close is a terminal state and
/// this method allows the communication listener to transition to this state in a
/// graceful manner.
/// </summary>
/// <param name="cancellationToken">Cancellation token</param>
/// <returns>
/// A <see cref="T:System.Threading.Tasks.Task">Task</see> that represents outstanding operation.
/// </returns>
public Task CloseAsync(CancellationToken cancellationToken)
{
WriteLog("Service Bus Communication Listnener closing");
_stopProcessingMessageTokenSource.Cancel();
//Wait for Message processing to complete..
ProcessingMessage.WaitOne();
ProcessingMessage.Dispose();
return(CloseImplAsync(cancellationToken));
}