public static IDisposable Indent(this IIndentedStringBuilder builder, string opening, string closing = null)
        {
            builder.AppendLine2(opening);
            var block = builder.Indent();

            return(new DisposableAction(() =>
            {
                block.Dispose();
                if (closing != null)
                {
                    builder.AppendLine2(closing);
                }
            }));
        }
 public IDisposable Indent(int count = 1)
 {
     TryWriteApply();
     return(_source.Indent(count));
 }