code: def str_kind(self, kind):
          
          if len(kind) == 0:
              return 'Nothing'
          elif len(kind) == 1:
              return kind[0].__name__
          elif len(kind) == 2:
              return kind[0].__name__ + ' or ' + kind[1].__name__
          else:
              return 'one of {' + ', '.join(t.__name__ for t in kind) + '}'
docs: Get a string describing a kind.