Refactoring Does Not Work With Closed Generic Type

**To Reproduce**
Steps to reproduce the behavior:
Create code that defines a closed generic - e.g. `ILogger<Customer>` and put the cursor on `ILogger`, and invoke the Rocks refactoring

**Expected behavior**
The [Rock] attribute is made targeting `ILogger<>`

**Actual behavior**
The [Rock] attribute is made targeting ... something else, either `Customer` or the containing type.