tests: Remove calls to private methods

testsuite/python/test_checkpoint.py

@@ -282,10 +282,8 @@ def test_integrator_SDM_gpu(self):
     @utx.skipIfMissingFeatures('LENNARD_JONES')
     @ut.skipIf('LJ' not in modes, "Skipping test due to missing mode.")
     def test_non_bonded_inter(self):
-        params1 = system.non_bonded_inter[
-            0, 0].lennard_jones._get_params_from_es_core()
-        params2 = system.non_bonded_inter[
-            3, 0].lennard_jones._get_params_from_es_core()
+        params1 = system.non_bonded_inter[0, 0].lennard_jones.get_params()
+        params2 = system.non_bonded_inter[3, 0].lennard_jones.get_params()
         reference1 = {'shift': 0.1, 'sigma': 1.3, 'epsilon': 1.2,
                       'cutoff': 2.0, 'offset': 0.0, 'min': 0.0}
         reference2 = {'shift': 0.1, 'sigma': 1.7, 'epsilon': 1.2,
@@ -294,13 +292,13 @@ def test_non_bonded_inter(self):
         self.assertEqual(params2, reference2)
 
     def test_bonded_inter(self):
-        state = system.part[1].bonds[0][0]._get_params_from_es_core()
+        state = system.part[1].bonds[0][0].params
         reference = {'r_0': 0.0, 'k': 1.0, 'r_cut': 0.0}
         self.assertEqual(state, reference)
         state = system.part[1].bonds[0][0].params
         self.assertEqual(state, reference)
         if 'THERM.LB' not in modes:
-            state = system.part[1].bonds[1][0]._get_params_from_es_core()
+            state = system.part[1].bonds[1][0].params
             reference = {'temp_com': 0., 'gamma_com': 0., 'temp_distance': 0.2,
                          'gamma_distance': 0.5, 'r_cut': 2.0, 'seed': 51}
             self.assertEqual(state, reference)