/// <summary>
/// Gets the reaction torque using the specified inv dt
/// </summary>
/// <param name="invDt">The inv dt</param>
/// <returns>The float</returns>
public override float GetReactionTorque(float invDt)
{
// TODO_ERIN not tested
Vec2 r = Math.Mul(Body2.GetXForm().R, LocalAnchor2 - Body2.GetLocalCenter());
Vec2 p = Impulse * jacobian.Linear2;
float l = Impulse * jacobian.Angular2 - Vec2.Cross(r, p);
return(invDt * l);
}