private static IEnumerable<Step> CreateStepsPrivate([NotNull] IEnumerable<StepDefinition> steps, [NotNull] ProcessorArgs args, [CanBeNull] IPipelineController controller = null)
        {
            Assert.ArgumentNotNull(steps, "steps");
              Assert.ArgumentNotNull(args, "args");

              foreach (StepDefinition stepDefinition in steps)
              {
            string argsName = stepDefinition.ArgsName.EmptyToNull();
            Step step = new Step(ProcessorManager.CreateProcessors(stepDefinition.ProcessorDefinitions, args, controller), argsName);
            Assert.IsNotNull(step, "Can't instantiate step");
            yield return step;
              }
        }