code: def _encrypt_request_bytes(request_bytes, key, iv):
      
  
      cipher = Cipher.AES.new(key, Cipher.AES.MODE_CBC, iv)
      request_bytes_padded = _pad_bytes(request_bytes)
  
      return cipher.encrypt(request_bytes_padded)
docs: :type request_bytes: bytes
      :type key: bytes
      :type iv: bytes
  
      :rtype: bytes