touch_model_timestamps_unless

# File activerecord/lib/active_record/insert_all.rb, line 276
        def touch_model_timestamps_unless(&block)
          return "" unless update_duplicates? && record_timestamps?

          model.timestamp_attributes_for_update_in_model.filter_map do |column_name|
            if touch_timestamp_attribute?(column_name)
              "#{column_name}=(CASE WHEN (#{updatable_columns.map(&block).join(" AND ")}) THEN #{model.quoted_table_name}.#{column_name} ELSE #{connection.high_precision_current_timestamp} END),"
            end
          end.join
        end