code: def _handle_result_by_key_slice(self, key_slice):
          
          invalid_options = ('key', 'keys', 'startkey', 'endkey')
          if any(x in invalid_options for x in self.options):
              raise ResultException(102, invalid_options, self.options)
  
          if isinstance(key_slice.start, ResultByKey):
              start = key_slice.start()
          else:
              start = key_slice.start
  
          if isinstance(key_slice.stop, ResultByKey):
              stop = key_slice.stop()
          else:
              stop = key_slice.stop
  
          if (start is not None and stop is not None and
                  isinstance(start, type(stop))):
              data = self._ref(startkey=start, endkey=stop, **self.options)
          elif start is not None and stop is None:
              data = self._ref(startkey=start, **self.options)
          elif start is None and stop is not None:
              data = self._ref(endkey=stop, **self.options)
          else:
              data = None
          return data
docs: Handle processing when the result argument provided is a key slice.