code: def setUp(self) -> None:
      self.search_space = SearchSpace(
          parameters=[
              RangeParameter(
                  "a",
                  lower=1,
                  upper=3,
                  parameter_type=ParameterType.FLOAT,
              ),
              ChoiceParameter(
                  "b",
                  parameter_type=ParameterType.STRING,
                  values=["a", "b", "c"],
              ),
              FixedParameter(
                  "c", parameter_type=ParameterType.STRING, value="a"
              ),
          ]
      )
      self.t = RemoveFixed(
          search_space=self.search_space,
          observations=[],
      )
  
file_path: Ax/ax/modelbridge/transforms/tests/test_remove_fixed_transform.py
imports: from copy import deepcopy
  from ax.core.observation import ObservationFeatures
  from ax.core.parameter import ChoiceParameter, FixedParameter, ParameterType, RangeParameter
  from ax.core.search_space import RobustSearchSpace, SearchSpace
  from ax.modelbridge.transforms.remove_fixed import RemoveFixed
  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 RemoveFixedTransformTest obj's underlying member method code with example usage: obj.setUp() without return types