code: def test_create_sampler(self):
      backend = create_hpo_backend()
      sampler = backend.create_sampler(SamplerType.TPE, {})
      assert sampler
  
file_path: BigDL/python/nano/test/automl/common/test_backend.py
imports: import pytest
  from unittest import TestCase
  from bigdl.nano.automl.hpo.backend import create_hpo_backend
  from bigdl.nano.automl.hpo.backend import SamplerType, PrunerType
label_desc: Use image node_id 1 for calling the TestHPOBackend obj's underlying member method code with example usage: obj.test_create_sampler() without return types