addToWorld method
Add the vehicle including its constraints to the world.
Implementation
void addToWorld(World world) {
final constraints = this.constraints;
wheelBodies.addAll([chassisBody]);
final bodies = wheelBodies;
for (int i = 0; i < bodies.length; i++) {
world.addBody(bodies[i]);
}
for (int i = 0; i < constraints.length; i++) {
world.addConstraint(constraints[i]);
}
world.addEventListener('preStep', _update);//_update.bind(this));
}