christy13/6006psets_ng — comment on commit 64b493a565eb396b6bcf162401f61c1c4137f13d
File: 5/code/rsa/ks_primitives.rb line 100
By pwnall:

```ruby
unless other.instance_of? Byte
raise ArgumentError, "Expected Byte, got #{other.class}"
end
```

This would help debug the test failure that you're having. If it helps you, chances are it'd help the students too. This kind of check would be useful across `ks_primitives.rb`, so consider wrapping in a method like `ensure_byte_instance(arg)` and calling `ensure_byte_instance other` here.