code: def test_load_policies(self):
      for name in POLICIES.keys():
          self.assertIsNotNone(get_policy_class(name))
  
imports: import unittest
  from ray.rllib.algorithms.registry import POLICIES, get_policy_class, get_policy_class_name, ALGORITHMS_CLASS_TO_NAME, ALGORITHMS
label_desc: Use image node_id 1 for calling the TestPolicies obj's underlying member method code with example usage: obj.test_load_policies() without return types