code: def _remove(self, ctx, table_name, record_id, column_values):
          
          vsctl_table = self._get_table(table_name)
          ovsrec_row = ctx.must_get_row(vsctl_table, record_id)
          for column, value in column_values:
              ctx.remove_column(ovsrec_row, column, value)
          ctx.invalidate_cache()
docs: :type column_values: list of (column, value_json)