{
    "report.generators": {
         "my-report": {
             "generator": "expression",
             "cols": {
                 "subject": null,
                 "difference": "percent_diff(mode(result_time_avg), mode(suite[subject_name = \"benchNothing\"][\"result_time_avg\"]))"
             }
         }
    }
}
---
phpbench run --report=my-report --executor=debug NothingBench.php --progress=none
---
+--------------+------------+
| subject      | difference |
+--------------+------------+
| benchNothing | 0.00%      |
+--------------+------------+

