code: def _load_maps_by_type(map_type):
      
      seq_maps = COLOR_MAPS[map_type]
  
      loaded_maps = {}
  
      for map_name in seq_maps:
          loaded_maps[map_name] = {}
  
          for num in seq_maps[map_name]:
              inum = int(num)
              colors = seq_maps[map_name][num]['Colors']
  
              bmap = BrewerMap(map_name, map_type, colors)
  
              loaded_maps[map_name][inum] = bmap
  
          max_num = int(max(seq_maps[map_name].keys(), key=int))
          loaded_maps[map_name]['max'] = loaded_maps[map_name][max_num]
  
      return loaded_maps
docs: Load all maps of a given type into a dictionary.
  
      Color maps are loaded as BrewerMap objects. Dictionary is
      keyed by map name and then integer numbers of defined
      colors. There is an additional 'max' key that points to the
      color map with the largest number of defined colors.
  
      Parameters
      ----------
      map_type : {'Sequential', 'Diverging', 'Qualitative'}
  
      Returns
      -------
      maps : dict of BrewerMap