code: def test_compute_gain(
      self, prior_values, process_values, obs_values, expected, atol
  ):
      self.estimator.initialize_covariances(
          prior_values, process_values, obs_values
      )
  
      res = self.estimator.compute_gain(None)
      self.assertAllClose(res, expected, atol=atol)
  
file_path: geomstats/geomstats/test_cases/learning/kalman_filter.py
imports: from geomstats.test.test_case import TestCase
label_desc: Use image node_id 1 for calling the KalmanFilterTestCase obj's underlying member method code with example usage: obj.test_compute_gain(prior_values, process_values, obs_values, expected, atol) without return types