def METHOD_NAME(self, number, row, validation_error):
    # NOTE: value order must match diff_headers order, so that row
    # values and column headers match in the UI when displayed
    values = tuple(row.get(col, "---") for col in self.diff_headers)
    self.invalid_rows.append(
        InvalidRow(number=number, validation_error=validation_error, values=values)
    )