code: def setUp(self) -> None:
      self.obsd_mid = ObservationData(
          metric_names=["m1", "m2"],
          means=np.array([0.5, 0.9]),
          covariance=np.array([[0.005, 0.0], [0.0, 0.005]]),
      )
      self.obsd_extreme = ObservationData(
          metric_names=["m1", "m2"],
          means=np.array([0.0, 1.0]),
          covariance=np.array([[1.0, 0.0], [0.0, 1.0]]),
      )
      self.obsd_nan_covars = ObservationData(
          metric_names=["m1", "m2"],
          means=np.array([0.5, 0.9]),
          covariance=np.array(
              [
                  [float("nan"), float("nan")],
                  [float("nan"), float("nan")],
              ]
          ),
      )
      self.t = InverseGaussianCdfY(
          search_space=None,
          observations=[],
      )
  
file_path: Ax/ax/modelbridge/transforms/tests/test_inverse_gaussian_cdf_y_transform.py
imports: from copy import deepcopy
  import numpy
  from ax.core.observation import ObservationData
  from ax.modelbridge.transforms.inverse_gaussian_cdf_y import InverseGaussianCdfY
  from ax.utils.common.testutils import TestCase
label_desc: Use image node_id 1 for calling the InverseGaussianCdfYTransformTest obj's underlying member method code with example usage: obj.setUp() without return types