fn test_sqrt_qfe() {
        // Coordinate x of q.
        let x = super::BN254TwistCurveFieldElement::new([
            BN254FieldElement::from_hex_unchecked(
                "1800deef121f1e76426a00665e5c4479674322d4f75edadd46debd5cd992f6ed",
            ),
            BN254FieldElement::from_hex_unchecked(
                "198e9393920d483a7260bfb731fb5d25f1aa493335a9e71297e485b7aef312c2",
            ),
        ]);

        let qfe_b = BN254TwistCurve::b();
        // The equation of the twisted curve is y^2 = x^3 + 3 /(9+u)
        let y_square = x.square() * &x + qfe_b;
        let y = super::sqrt_qfe(&y_square, 0).unwrap();

        // Coordinate y of q.
        let y_expected = super::BN254TwistCurveFieldElement::new([
            BN254FieldElement::from_hex_unchecked(
                "12c85ea5db8c6deb4aab71808dcb408fe3d1e7690c43d37b4ce6cc0166fa7daa",
            ),
            BN254FieldElement::from_hex_unchecked(
                "090689d0585ff075ec9e99ad690c3395bc4b313370b38ef355acdadcd122975b",
            ),
        ]);

        let value_y = y.value();
        let value_y_expected = y_expected.value();

        assert_eq!(value_y[0].clone(), value_y_expected[0].clone());
        assert_eq!(value_y[1].clone(), value_y_expected[1].clone());
    }
We took the q1 point of the test two_pairs_of_points_match_1 from pairing.rs
to get the values of x and y.
crates/math/src/elliptic_curve/short_weierstrass/curves/bn_254/sqrt.rs