code: def scroll(self, value, mode='relative'):
          
          self._check_executed()
          if mode == 'relative':
              r = self.rownumber + value
          elif mode == 'absolute':
              r = value
          else:
              raise ProgrammingError("unknown scroll mode %s" % repr(mode))
          if r < 0 or r >= len(self._rows):
              raise IndexError("out of range")
          self.rownumber = r
docs: Scroll the cursor in the result set to a new position according
          to mode.
  
          If mode is 'relative' (default), value is taken as offset to
          the current position in the result set, if set to 'absolute',
          value states an absolute target position.