public long getStartInMs() {
        return this.startInMs;
    }
@Test
    void testStartInMs() {
        Pane<?> pane = mock(Pane.class);
        long startTime = System.currentTimeMillis();
        when(pane.getStartInMs()).thenReturn(startTime);
        assertEquals(startTime, pane.getStartInMs());
    }