BExIS.Dcm.CreateDatasetWizard.CreateTaskmanager.findPrev C# (CSharp) Метод

        private StepInfo findPrev(StepInfo child)
        {
            StepInfo parent = child.Parent;
            int index = parent.Children.IndexOf(child);

            if (IsRoot(parent))
            {
                if (index > 0)
                    return Last(parent.Children.ElementAt(index - 1));
                else
                    return new StepInfo("");
            }
            else
            {

                if (index > 0)
                {
                    StepInfo pStep = parent.Children.ElementAt(index - 1);
                    if (pStep.Children.Count == 0)
                        return pStep;
                    else
                        return findLast(pStep);
                }
                else
                    return parent;
            }
        }