code: def _test_step(self, step):
      state = self.intercept
      result = step(self.function_linear, state, 0.0, self.dt)
      expected = state + 2 * self.dt
  
      self.assertAllClose(result, expected)
  
file_path: geomstats/tests/tests_geomstats/test_integrator.py
imports: import pytest
  import geomstats.backend
  import geomstats.integrator
  from geomstats.geometry.euclidean import Euclidean
  from geomstats.geometry.matrices import Matrices
  from geomstats.test.test_case import TestCase
label_desc: Use image node_id 3 for calling the TestIntegrator obj's underlying member method code with example usage: obj._test_step(step) without return types