code: def testAdd(self):
      memory = circular_replay_buffer.ReplayBuffer(
          stack_size=STACK_SIZE,
          replay_capacity=5,
          batch_size=BATCH_SIZE,
      )
      self.assertEqual(memory.cursor(), 0)
      zeros = np.zeros(OBSERVATION_SHAPE)
      memory.add(observation=zeros, action=0, reward=0, terminal=0)
      # Check if the cursor moved STACK_SIZE -1 padding adds + 1, (the one above).
      self.assertEqual(memory.cursor(), STACK_SIZE)
  
imports: import tempfile
  import unittest
  import numpy
  import numpy.testing
  import torch
  from reagent.replay_memory import circular_replay_buffer
label_desc: Use image node_id 4 for calling the ReplayBufferTest obj's underlying member method code with example usage: obj.testAdd() without return types