+ void set_angular_velocity(Msp::Geometry::Angle<float>);
+ void add_force(const Msp::LinAl::Vector<float, 2> &);
+ void add_force(const Msp::LinAl::Vector<float, 2> &, const Msp::LinAl::Vector<float, 2> &);
+ void add_torque(float);
+ void clear_forces();