private void RenderIssue([NotNull] string group, [NotNull] ValidationIssue issue)
        {
            Debug.ArgumentNotNull(group, nameof(group));
            Debug.ArgumentNotNull(issue, nameof(issue));

            var path = GetPath(group, issue);

            var collection = Issues.FindPath(path, GetNode);

            if (collection == null)
            {
                return;
            }

            var treeViewItem = GetLeaf(issue, issue.Text, issue.Icon);

            collection.Add(treeViewItem);
        }