private static void ParallelCore_BeforeProcessSingleItem(Tools.ProducerConsumer.IProcessingStage <string, int> sender, string item)
 {
     Console.WriteLine($"Running command '{item}'");
 }
 private static void ParallelCore_AfterProcessSingleItem(Tools.ProducerConsumer.IProcessingStage <string, int> sender, string item, int processedItem)
 {
     Console.WriteLine($"== Command {item} exited with code {processedItem} ==");
 }