2
Ask HN: How do you separate intentional test boilerplate from real duplication?
(news.ycombinator.com)
TBH I would not use a duplicate code detector at all. That would solve the problem. I tend to find excessive deduplication to be a bigger problem then have some unnecessary duplication.
If you need a tool to find duplicate code you are probably down the route of excess. They only really time you need to deduplicate code is when it causes a problem for maintenance. Then it is typically trivially easy to find it without a special tool.