Created Issue: Should be single [12313]

hey guys, I've run into this a couple times and implemented work-around, but I finally got around to creating proper extension methods for fluent assertions, it would be nice if it ended up as a native feature of Fluent Assertions.

I'm hoping that you can re purpose the testing suite on Should().Contain() to point at the throwing Should().ContainSingle(TItem) implementation.

cheers.