code: def peekitem(self, index=-1):
          
          key = self._list[index]
          return key, self[key]
docs: Return (key, value) item pair at index.
  
          Unlike ``popitem``, the sorted dictionary is not modified. Index
          defaults to -1, the last/greatest key in the dictionary. Specify
          ``index=0`` to lookup the first/least key in the dictiony.
  
          If index is out of range, raise IndexError.