An easy to use factory for creating bodies
        public static Fixture CreateEdge(World world, Vector2 start, Vector2 end, Object userData)
        {
            Body body = BodyFactory.CreateBody(world);

            return(CreateEdge(start, end, body, userData));
        }
        public static Fixture CreateCircle(World world, float radius, float density, Vector2 position, Object userData)
        {
            Body body = BodyFactory.CreateBody(world, position);

            return(CreateCircle(radius, density, body, userData));
        }