override index name in test files

[daureg]

I don't like the situation when I'm forced to use this tool, but when it does happen it works very well 😅

However, there one feature I could use, and I'm not sure what's the cleanest implementation.

Let's say I have 2 environments (live & staging) with different index names referring to the same data (say index_11 in live and index_11_snapshot_20211105 in staging). I don't want to duplicate my test files to run separately live and staging test (so all test files should have "index": "index_11"), but I when I'm developing and testing against staging, I would like to override "index": "index_11" from the file by "index": "index_11_snapshot_20211105" (either with a command line argument or environment variable).
Could it be done in LoadTestCaseSetup() for instance?