Theoretically, a test may have depended on the attribute of the old `TypeWithCtor` that it only had a single constructor. It's really difficult to tell, and having only appended more members doesn't guarantee anything.

The only way to be sure is to identify all the old tests that relies on this class, and deliberately revert the SUT's implementation so that these tests fail. This proves that no false negatives were introduced, and then one can re-implement the SUT correctly again.

That said, the new `TypeWithCtor` class seems to define its `Ctor` property like this:

```C#
public static ConstructorInfo Ctor
{
    get
    {
        return typeof(TypeWithCtor).GetConstructors().Single(c => c.GetParameters().Length == 0);
    }
}
```

So it looks to me that the members *did* change, too...