Function arc_works

src/canvas.rs:1442–1448

()

    #[test]
    fn arc_works() {
        let mut canvas = Canvas::new();
        canvas.draw_arc(0.0, 0.0, 1.0, 30.0, 60.0);
        let b: &str = "p=pat.Arc((0,0),2*1,2*1,theta1=30,theta2=60,angle=0,edgecolor='#427ce5')\n\
                       plt.gca().add_patch(p)\n";
        assert_eq!(canvas.buffer, b);
    }

    #[test]
    fn arrow_woks() {