code: def _handle_result_by_key(self, key):
          
          invalid_options = ('key', 'keys', 'startkey', 'endkey')
          if any(x in invalid_options for x in self.options):
              raise ResultException(102, invalid_options, self.options)
          return self._ref(key=key, **self.options)
docs: Handle processing when the result argument provided is a document key.