Actually ...  as the test module already contains the name, I'm not sure this matters after all.
If the test module targets a top-level module function, there are no static named 'components' of a function to write individual tests for, so maybe the division and naming of test classes can be ad-hoc.

That seems to be the style of [test_export_geotiff](https://github.com/SciTools/iris/blob/master/lib/iris/tests/unit/experimental/raster/test_export_geotiff.py) - which I think was first ever newstyle unit-test