code: def calculate_cut_coords_by_zoom(
          coord, metatile_zoom, cfg_tile_sizes, max_zoom):
      
  
      tile_sizes_by_zoom = calculate_sizes_by_zoom(
          coord, metatile_zoom, cfg_tile_sizes, max_zoom)
  
      cut_coords_by_zoom = {}
      for nominal_zoom, tile_sizes in tile_sizes_by_zoom.iteritems():
          cut_coords = []
          for tile_size in tile_sizes:
              cut_coords.extend(metatile_children_with_size(
                  coord, metatile_zoom, nominal_zoom, tile_size))
  
          cut_coords_by_zoom[nominal_zoom] = cut_coords
  
      return cut_coords_by_zoom
docs: Returns a map of nominal zoom to the list of cut coordinates at that
      nominal zoom.
  
      Note that max_zoom should be the maximum coordinate zoom, not nominal
      zoom.