code: def _filter_rows(self, rows, visible_columns=None):
          
          if visible_columns is None:
              visible_columns = self.visible_columns
          filtered_row = []
          for idx, name in enumerate(self.columns.keys()):
              if name in self.visible_columns:
                  filtered_row.append(rows[idx])
          return filtered_row
docs: Filter `rows` based on the visible columns.