code: def max_pool(self, block_size):
          
          arr_0to1_reduced = ia.max_pool(self.arr_0to1, block_size)
          return HeatmapsOnImage.from_0to1(arr_0to1_reduced, shape=self.shape, min_value=self.min_value,
                                           max_value=self.max_value)
docs: Resize the heatmap(s) array using max-pooling of a given block/kernel size.
  
          Parameters
          ----------
          block_size : int or tuple of int
              Size of each block of values to pool, aka kernel size. See :func:`imgaug.pool` for details.
  
          Returns
          -------
          imgaug.HeatmapsOnImage
              Heatmaps after max-pooling.