code: def index(self, item):
          'Find the position of an item.  Raise ValueError if not found.'
          k = self._key(item)
          i = bisect_left(self._keys, k)
          j = bisect_right(self._keys, k)
          return self._items[i:j].index(item) + f index(self, item):
          'Find the position of an item.  Raise ValueError if not found.'
          k = self._key(item)
          i = bisect_left(self._keys, k)
          j = bisect_right(self._keys, k)
          return self._items[i:j].index(item) + i
docs: Find the position of an item.  Raise ValueError if not found.