code: func (it *iterator4List) Next() Row {
  	if it.chkCursor >= it.li.NumChunks() {
  		it.chkCursor = it.li.NumChunks() + 1
  		return it.End()
  	}
  	chk := it.li.GetChunk(it.chkCursor)
  	row := chk.GetRow(it.rowCursor)
  	it.rowCursor++
  	if it.rowCursor == chk.NumRows() {
  		it.rowCursor = 0
  		it.chkCursor++
  	}
  	return row
  }
docs: // Next implements the Iterator interface.