code: def check_colormap(cmap):
      
      names = set(['BrBG', 'PiYG', 'PRGn', 'PuOr', 'RdBu', 'RdGy', 'RdYlBu', 'RdYlGn', 'Spectral',
                   'Blues', 'BuGn', 'BuPu', 'GnBu', 'Greens', 'Greys', 'Oranges', 'OrRd', 'PuBu',
                   'PuBuGn', 'PuRd', 'Purples', 'RdPu', 'Reds', 'YlGn', 'YlGnBu', 'YlOrBr', 'YlOrRd',
                   'Accent', 'Dark2', 'Paired', 'Pastel1', 'Pastel2', 'Set1', 'Set2', 'Set3', 'Lightning'])
      if cmap not in names:
          raise Exception("Invalid cmap '%s',  must be one of %s" % (cmap, names))
      else:
          return cmap
docs: Check if cmap is one of the colorbrewer maps