only note, that to see which one is missing it is useful to add also message like
```
['f1', 'f2', 'f3', 'f4', 'f5', 'f6', 'f7', 'f8'].each do |key|
  expect(Yast::InstFunctions.feature_ignored?(key)).to be_true, "key #{key} is not ignored"
end
```