code: def encrypt(self, raw):
          
          raw = self._pad(raw)
          iv = Random.new().read(AES.block_size)
          cipher = AES.new(self.key, AES.MODE_CBC, iv)
          return base64.urlsafe_b64encode(iv + cipher.encrypt(raw))
docs: Encryptes the parameter raw.
  
          :type raw: bytes
          :rtype: str
  
          :param: bytes to be encrypted.
  
          :return: A base 64 encoded string.