code: def _get_input_data(self, request):
          
          # only PUT and POST should provide data
          if not self._is_data_method(request):
              return None
  
          content = [row for row in request.read()]
          content = ''.join(content) if content else None
          return self._parse_input_data(content, request) if content else None
docs: If there is data, parse it, otherwise return None.