
struct Vector3 {
    x: f64 = 0.0
    y: f64 = 0.0
    z: f64 = 0.0
}


struct Quaternion{
    xyz: Vector3
    w: f64 = 0.0
}

struct Twist{
    linear: Vector3 
    angular: Vector3 
}

struct Twist{

    // This expresses velocity in free space with uncertainty.
    twist: Twist 

    // Row-major representation of the 6x6 covariance matrix
    // The orientation parameters use a fixed-axis representation.
    // In order, the parameters are:
    // (x, y, z, rotation about X axis, rotation about Y axis, rotation about Z axis)
    covariance: float64[36] 
}