Initial parameter for hyperopt

Not sure this is the right forum to discuss but I have a question on using the initial parameter for hyperopt documented at:

 https://docs.ray.io/en/latest/tune/examples/hyperopt_example.html

If a parameter is a list, the search will crash with error "“GarbageCollected”, e.g.

 initial_params = [{"a": [1, 2], "b": [1, 2, 3]},]

It works fine when the initial parameter contains only single value, e.g.

 initial_params = [{"a": 1, "b": 1},]

I can post a short code to reproduce this if necessary