Used if you want to change language in test expression in a unitizer when
the actual results of running the expressions is unchanged. This is useful
if you decided to rename functions, etc., without having to re-run the entire
unitize process since unitize matches tests based on
expressions.
logical(1L) set to FALSE if you want to allow this to
run in non-interactive mode, but warnings will be suppressed and will
proceed without prompting, obviously...