code: def _raise_error_if_column_exists(dataset, column_name = 'dataset',
                              dataset_variable_name = 'dataset',
                              column_name_error_message_name = 'column_name'):
      
      err_msg = 'The SFrame {0} must contain the column {1}.'.format(
                                                  dataset_variable_name,
                                               column_name_error_message_name)
      if column_name not in dataset.column_names():
        raise ToolkitError(str(err_msg))
docs: Check if a column exists in an SFrame with error message.