docs: def mysql_aes_decrypt(encrypted_val, key):
      """Mysql AES decrypt value with secret key.
  
      :param encrypted_val: Encrypted value.
      :param key: The AES key.
      :returns: The AES value decrypted.
      """
      assert isinstance(encrypted_val, binary_type) \
          or isinstance(encrypted_val, text_type)
      assert isinstance(key, binary_type) or isinstance(key, text_type)
      k = _mysql_aes_key(_to_binary(key))
      d = _mysql_aes_engine(_to_binary(k)).decryptor()
      return _mysql_aes_unpad(d.update(_to_binary(encrypted_val)) + d.finalize())