The original idea was that "roundtrips" would test against converting ncdata-> "format-x" ->ncata and the reverse.
But actually, they are now testing the equivalence of (loading) netcdf -> "x" and netcdf -> ncdata -> "x", and equivalent for saves
i.e. the equivalence of "direct" + "via-ncdata" save + load.
Renaming might be sensible
The original idea was that "roundtrips" would test against converting ncdata-> "format-x" ->ncata and the reverse. But actually, they are now testing the equivalence of (loading) netcdf -> "x" and netcdf -> ncdata -> "x", and equivalent for saves