code: def test_symp_euler(self, test_state, step_size, expected):
      # TODO: migrate test to integrators?
      result = self.space.metric.symp_euler(
          hamiltonian=self.space.metric.hamiltonian, step_size=step_size
      )(test_state)
      self.assertAllClose(result, expected)
  
file_path: geomstats/tests/tests_geomstats/test_geometry/test_sub_riemannian_metric.py
imports: import geomstats.backend
  from geomstats.geometry.heisenberg import HeisenbergVectors
  from geomstats.geometry.sub_riemannian_metric import SubRiemannianMetric
  from geomstats.test.parametrizers import DataBasedParametrizer
  from geomstats.test_cases.geometry.sub_riemannian_metric import SubRiemannianMetricTestCase
  from .data.sub_riemannian_metric import SubRiemannianMetricCometricTestData, SubRiemannianMetricFrameTestData
label_desc: Use image node_id 1 for calling the TestSubRiemannianMetricCometric obj's underlying member method code with example usage: obj.test_symp_euler(test_state, step_size, expected) without return types