code: def test_nonzero_padding(self, max_sequence_length, padding):
      adder = adders.EpisodeAdder(
          self.client,
          max_sequence_length + padding,
          padding_fn=lambda s, d: np.zeros(s, d) - 1,
      )
  
      # Create a simple trajectory to add.
      observations = range(max_sequence_length)
      first, steps = test_utils.make_trajectory(observations)
  
      expected_episode = test_utils.make_sequence(observations)
      for _ in range(padding):
          expected_episode.append((-1, -1, -1.0, -1.0, False, ()))
  
      self.run_test_adder(
          adder=adder,
          first=first,
          steps=steps,
          expected_items=[expected_episode],
          signature=adder.signature(*test_utils.get_specs(steps[0])),
      )
  
file_path: acme/acme/adders/reverb/episode_test.py
imports: from acme.adders.reverb import episode
  from acme.adders.reverb import test_utils
  import numpy
  from absl.testing import absltest
  from absl.testing import parameterized
label_desc: Use image node_id 4 for calling the EpisodeAdderTest obj's underlying member method code with example usage: obj.test_nonzero_padding(max_sequence_length, padding) without return types