code: def add_xml_declaration(fn):
      
      @wraps(fn)
      def add_xml_declaration_decorator(*args, **kwargs):
          return '<?xml version="1.0" encoding="UTF-8"?>\n\n' + fn(
              *args,
              **kwargs
          )
  
      return add_xml_declaration_decorator
docs: Decorator to add header with XML version declaration to output from FN.