vector transformed by quaternion

public static Vector3 Transform(Vector3 value, Quaternion rotation)
{
    Vector3 vector;
    float num12 = rotation.X + rotation.X;
    float num2 = rotation.Y + rotation.Y;
    float num = rotation.Z + rotation.Z;
    float num11 = rotation.W * num12;
    float num10 = rotation.W * num2;
    float num9 = rotation.W * num;
    float num8 = rotation.X * num12;
    float num7 = rotation.X * num2;
    float num6 = rotation.X * num;
    float num5 = rotation.Y * num2;
    float num4 = rotation.Y * num;
    float num3 = rotation.Z * num;
    float num15 = ((value.X * ((1f - num5) - num3)) + (value.Y * (num7 - num9))) + (value.Z * (num6 + num10));
    float num14 = ((value.X * (num7 + num9)) + (value.Y * ((1f - num8) - num3))) + (value.Z * (num4 - num11));
    float num13 = ((value.X * (num6 - num10)) + (value.Y * (num4 + num11))) + (value.Z * ((1f - num8) - num5));
    vector.X = num15;
    vector.Y = num14;
    vector.Z = num13;
    return vector;
}