code: def test_aes256_cbc(self):
      enc_str = encrypt_with_AES_CBC(
          self.random_str, "analytics-zoo", "intel-analytics", 256
      )
      dec_str = decrypt_with_AES_CBC(
          enc_str, "analytics-zoo", "intel-analytics", 256
      )
      assert (
          dec_str == self.random_str
      ), "Check AES CBC 128 encryption and decryption result"
  
file_path: analytics-zoo/pyzoo/test/zoo/common/test_encryption_utils.py
imports: from unittest import TestCase
  import pytest
  import string
  import random
  from zoo.common.encryption_utils import *
label_desc: Use image node_id 7 for calling the TestEncryption obj's underlying member method code with example usage: obj.test_aes256_cbc() without return types