code: def test_initialize_from_array(self, vectors):
      accumulator = variance_util.MeanCovAccumulator()
      accumulator.update(vectors)
      expected_mean = np.mean(vectors, axis=0)
      expected_covariance = np.cov(vectors, rowvar=False).ravel()
      actual_mean = accumulator.mean
      actual_covariance = accumulator.covariance.ravel()
  
      self.assertEqual(expected_mean.size, actual_mean.size)
      self.assertEqual(expected_covariance.size, actual_covariance.size)
      for expected, actual in zip(expected_mean, actual_mean):
          self.assertAlmostEqual(expected, actual)
      for expected, actual in zip(
          expected_covariance, actual_covariance
      ):
          self.assertAlmostEqual(expected, actual)
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from tensorflow_data_validation.utils import variance_util
label_desc: Use image node_id 1 for calling the MeanCovAccumulatorTest obj's underlying member method code with example usage: obj.test_initialize_from_array(vectors) without return types