code: def test_agent(self):
      agent = TestAgent(self.alg)
      obs = torch.randn(10, 4)
      act_output = agent.predict(obs)
      self.assertIsNotNone(act_output)
  
imports: import numpy
  import unittest
  import os
  import torch
  import torch.nn
  import torch.optim
  import parl
label_desc: Use image node_id 2 for calling the ACAgentBaseTest obj's underlying member method code with example usage: obj.test_agent() without return types