Yes, it won't have the same effect if someone steals the reference to the newly created hashset.
In this case, that chance is extremely low.

I'm not afraid of dependencies, I just think that they should be treated with caution.
Is it really worth it to add 2.1MB to your artifact (and to any artifact which uses your artifact as a dependency) just so you can use one utility method? I think Google Go has some wise philosophies in this regard.