def __raw_add(self, e_x, e_y, exponent):
        """return the integer E(x + y) given ints E(x) and E(y).
        """
        ciphertext =  e_x * e_y % self.public_key.nsquare

        return PaillierEncryptedNumber(self.public_key, ciphertext, exponent)
return the integer E(x + y) given ints E(x) and E(y).
        
fedlearner/model/crypto/paillier.py