code: def index(self, key, start=None, stop=None):
          
          # pylint: disable=arguments-differ
          temp, value = key
          pos = self._list.index(temp, start, stop)
          if value == self._dict[temp]:
              return pos
          else:
              raise ValueError('{0!r} is not in dict'.format(key))
docs: Return the smallest *k* such that `itemssview[k] == key` and `start <= k
          < end`.  Raises `KeyError` if *key* is not present.  *stop* defaults
          to the end of the set.  *start* defaults to the beginning.  Negative
          indexes are supported, as for slice indices.