This method encrypts the content.

def _cbc_encrypt(self, content, final_key):
        """This method encrypts the content."""

        aes = AES.new(final_key, AES.MODE_CBC, self._enc_iv)
        padding = (16 - len(content) % AES.block_size)

        for _ in range(padding):
            content += chr(padding).encode()

        temp = bytes(content)
        return aes.encrypt(temp)