code: def get_aws_index(self):
          
          if self.aws_index is not None:
              return self.aws_index
          tile_info_list = get_tile_info(self.tile_name, self.datetime, all_tiles=True)
          if not tile_info_list:
              raise ValueError('Cannot find aws_index for specified tile and time')
  
          if self.data_source is DataSource.SENTINEL2_L2A:
              for tile_info in sorted(tile_info_list, key=self._parse_aws_index):
                  try:
                      self.aws_index = self._parse_aws_index(tile_info)
                      self.get_tile_info()
                      return self.aws_index
                  except AwsDownloadFailedException:
                      pass
  
          return self._parse_aws_index(tile_info_list[0])
docs: Returns tile index on AWS. If `tile_index` was not set during class initialization it will be determined
          according to existing tiles on AWS.
  
          :return: Index of tile on AWS
          :rtype: int