code: def normalization_factor_init_test_data(self):
      data = [
          dict(
              expected_normalization_factor_var=0.00291884,
              expected_phi_inv_var=0.00562326,
              atol=1e-6,
          )
      ]
      return self.generate_tests(data)
  
file_path: geomstats/tests/tests_geomstats/test_learning/data/expectation_maximization.py
imports: import geomstats.backend
  from geomstats.test.data import TestData
  from ._base import BaseEstimatorTestData
label_desc: Use image node_id 1 for calling the GaussianMixtureModelTestData obj's underlying member method code with example usage: obj.normalization_factor_init_test_data() and returns: self