private static string BuildSupportedTagsMessage(IXPathNavigable node, IEnumerable<SupportedTagAttribute> tags)
{
var supportedTags = tags.Select(x => x.ToString()).Aggregate((i, j) => i + Environment.NewLine + j);
var navigator = node.GetNavigator();
var message = string.Format(
CultureInfo.CurrentCulture,
"The specified '{0}' element is invalid. The supported tags for this node are: {1}",
navigator.Name,
supportedTags);
return message;
}