code: def test_train_and_eval_mode(self):
      agent = TestAgent(self.alg)
      obs = torch.randn(3, 10)
      agent.train()
      self.assertTrue(agent.training)
      train_mode_output = agent.predict(obs).detach().numpy()
      agent.eval()
      self.assertFalse(agent.training)
      eval_mode_output = agent.predict(obs).detach().numpy()
      self.assertTrue((train_mode_output == eval_mode_output).all())
  
imports: import numpy
  import unittest
  import os
  import torch
  import torch.nn
  import torch.optim
  import parl
label_desc: Use image node_id 6 for calling the AgentBaseTest obj's underlying member method code with example usage: obj.test_train_and_eval_mode() without return types