docs: def block_reduce(self, block_size, how=np.ma.mean):
          '''
          geo.block_reduce(block_size, how=func)
  
          Returns copy of raster aggregated to smaller resolution, by adding cells.
          Default: func=np.ma.mean
          '''
          raster2 = block_reduce(self.raster, block_size, func=how)
          geot = self.geot
          geot = (geot[0], block_size[0] * geot[1], geot[2], geot[3], geot[4],
                  block_size[1] * geot[-1])
          return GeoRaster(raster2, geot, nodata_value=self.nodata_value,\
                          projection=self.projection, datatype=self.datatype)