code: def test_train_mode(self):
      embeds = self.create_random_shared_embedding()
      embeds.train()
      x = embeds(np.array([0, 2]))
      self.assertFalse(x.stop_gradient)
  
imports: import time
  import unittest
  import numpy
  import paddle
  from pgl.utils.shared_embedding import SharedEmbedding
label_desc: Use image node_id 5 for calling the TestSharedEmebdding obj's underlying member method code with example usage: obj.test_train_mode() without return types