What do you want to test? Another reply has mentioned the 15K USD TotalPhase device, which I'd love to use one day.
For "home" testing, I've used a USB C -> NVMe enclosure (UGreen is my favourite) with a half decent NVMe drive in it. Does the drive reach 1 gigabyte / second sustained read/write? Congrats, the cable supports 10 gigabit.