Please make sure that this is a bug.

System information

• OS Platform: linux
• Python version:3.9
• HyperGBM version: 0.3 or 0.2.5.7
• hboard: 0.1.1

Describe the current behavior
if make_experiment() set down_sample_search=True and webui=True, hypernets will report the following warning, which results in invalid search steps.

10-26 11:32:31 W hypernets.e.init.py 1463 - Exception: Unseen Step class SpaceSearchWithDownSampleStep
Traceback (most recent call last):
File "/home/jiapj/miniconda3/envs/gbm_venv_3.9/lib/python3.9/site-packages/hypernets/experiment/_experiment.py", line 86, in run
callback.experiment_start(self)
File "/home/jiapj/miniconda3/envs/gbm_venv_3.9/lib/python3.9/site-packages/hboard/callbacks.py", line 125, in experiment_start
super(WebVisExperimentCallback, self).experiment_start(exp)
File "/home/jiapj/miniconda3/envs/gbm_venv_3.9/lib/python3.9/site-packages/hypernets/experiment/_callback.py", line 533, in experiment_start
d = ExperimentExtractor(exp).extract()
File "/home/jiapj/miniconda3/envs/gbm_venv_3.9/lib/python3.9/site-packages/hypernets/experiment/_extractor.py", line 670, in extract
steps_meta = [self.extract_step(i, step) for i, step in enumerate(exp.steps)]
File "/home/jiapj/miniconda3/envs/gbm_venv_3.9/lib/python3.9/site-packages/hypernets/experiment/_extractor.py", line 670, in
steps_meta = [self.extract_step(i, step) for i, step in enumerate(exp.steps)]
File "/home/jiapj/miniconda3/envs/gbm_venv_3.9/lib/python3.9/site-packages/hypernets/experiment/_extractor.py", line 633, in extract_step
raise Exception(f"Unseen Step class {step_type} ")