I found this during adding deprecations for RW access in
the base class defines doOpenIfChanged(boolean readOnly), but MultiReader and ParallelReader "override" this method with a signature doOpenIfChanged(doClone) and missing @Override. This makes consumers calling IR.openIfChanged(boolean readOnly) do the wrong thing. Instead they should get UOE like for the other unimplemented doOpenIfChanged methods in MR and PR.
Easy fix is to rename and hide this internal "reopen" method, like DirectoryReader,...