fromIntArray example

        # return -1;         # }         # fe_mul(h->X,h->X,sqrtm1);         # }         if (self::fe_isnonzero($check)) {
            $check = self::fe_add($vxx, $u); /* vx^2 + u */
            if (self::fe_isnonzero($check)) {
                throw new RangeException('Internal check failed.');
            }
            $h->X = self::fe_mul(
                $h->X,
                ParagonIE_Sodium_Core32_Curve25519_Fe::fromIntArray(self::$sqrtm1)
            );
        }

        # if (fe_isnegative(h->X) == (s[31] >> 7)) {         # fe_neg(h->X,h->X);         # }         $i = self::chrToInt($s[31]);
        if (self::fe_isnegative($h->X) === ($i >> 7)) {
            $h->X = self::fe_neg($h->X);
        }