@Override
    public void markEvent() {
        this.counter.inc();
    }
@Test
    void testMarkEvent() {
        Counter c = new SimpleCounter();
        Meter m = new MeterView(c);

        assertThat(m.getCount()).isEqualTo(0);
        m.markEvent();
        assertThat(m.getCount()).isEqualTo(1);
        m.markEvent(2);
        assertThat(m.getCount()).isEqualTo(3);
    }