code: def test_observation_model(self, state, expected, atol):
      res = self.model.observation_model(state)
      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 3 for calling the LocalizationTestCase obj's underlying member method code with example usage: obj.test_observation_model(state, expected, atol) without return types