code: def parser(format_name, ext_names=None):
      
  
      def decorator(cls):
          format_name_lower = format_name.lower()
          if ext_names is None:
              _ext_format_mapping[format_name_lower] = format_name_lower
          else:
              for ext in to_list(ext_names):
                  _ext_format_mapping[ext.lower()] = format_name_lower
          _format_parser_mapping[format_name_lower] = cls()
          return cls
  
      return decorator
docs: Decorate a parser class to register it.
  
      :param format_name: standard format name
      :param ext_names: supported extension name