code: def setUp(self) -> None:
      self.search_space = SearchSpace(
          parameters=[
              RangeParameter(
                  "x",
                  lower=1,
                  upper=3,
                  parameter_type=ParameterType.FLOAT,
              ),
              RangeParameter(
                  "a",
                  lower=1,
                  upper=2,
                  parameter_type=ParameterType.INT,
              ),
              ChoiceParameter(
                  "b",
                  parameter_type=ParameterType.STRING,
                  values=["a", "b", "c"],
              ),
              ChoiceParameter(
                  "c",
                  parameter_type=ParameterType.BOOL,
                  values=[True, False],
                  is_ordered=False,
              ),
              ChoiceParameter(
                  "d",
                  parameter_type=ParameterType.FLOAT,
                  values=[1.0, 10.0, 100.0],
                  is_ordered=True,
              ),
          ],
          parameter_constraints=[
              ParameterConstraint(
                  constraint_dict={"x": -0.5, "a": 1}, bound=0.5
              )
          ],
      )
      self.t = OneHot(
          search_space=self.search_space,
          observations=[],
      )
      self.t2 = OneHot(
          search_space=self.search_space,
          observations=[],
          config={"rounding": "randomized"},
      )
  
      self.transformed_features = ObservationFeatures(
          parameters={
              "x": 2.2,
              "a": 2,
              "b" + OH_PARAM_INFIX + "_0": 0,
              "b" + OH_PARAM_INFIX + "_1": 1,
              "b" + OH_PARAM_INFIX + "_2": 0,
              # Only two choices => one parameter.
              "c" + OH_PARAM_INFIX: 0,
              "d": 10.0,
          }
      )
      self.observation_features = ObservationFeatures(
          parameters={"x": 2.2, "a": 2, "b": "b", "c": False, "d": 10.0}
      )
  
file_path: Ax/ax/modelbridge/transforms/tests/test_one_hot_transform.py
imports: from copy import deepcopy
  from ax.core.observation import ObservationFeatures
  from ax.core.parameter import ChoiceParameter, ParameterType, RangeParameter
  from ax.core.parameter_constraint import ParameterConstraint
  from ax.core.search_space import RobustSearchSpace, SearchSpace
  from ax.modelbridge.transforms.one_hot import OH_PARAM_INFIX, OneHot
  from ax.utils.common.testutils import TestCase
  from ax.utils.testing.core_stubs import get_robust_search_space
label_desc: Use image node_id 1 for calling the OneHotTransformTest obj's underlying member method code with example usage: obj.setUp() without return types