code: def test_Init(self) -> None:
      self.assertEqual(self.t.Ymean, {"m1": 1.0, "m2": 1.5})
      self.assertEqual(self.t.Ystd, {"m1": 1.0, "m2": sqrt(1 / 3)})
      with self.assertRaises(DataRequiredError):
          StandardizeY(
              search_space=None,
              observations=[],
          )
  
imports: from copy import deepcopy
  from math import sqrt
  from typing import List
  import numpy
  from ax.core.metric import Metric
  from ax.core.objective import Objective
  from ax.core.observation import Observation, ObservationData, ObservationFeatures
  from ax.core.optimization_config import OptimizationConfig
  from ax.core.outcome_constraint import OutcomeConstraint, ScalarizedOutcomeConstraint
  from ax.core.types import ComparisonOp
  from ax.exceptions.core import DataRequiredError
  from ax.modelbridge.transforms.standardize_y import StandardizeY
  from ax.utils.common.testutils import TestCase
label_desc: Use image node_id 2 for calling the StandardizeYTransformTest obj's underlying member method code with example usage: obj.test_Init() without return types