    @Test
    public void testSendMetricNotFilter() {

        sink.filter = new NotFilter(new MatchKey(metric.getKey()));
        doNothing().when(childSink).sendMetric(metric);
        ArgumentCaptor<Metric> captor = ArgumentCaptor.forClass(Metric.class);

        sink.sendMetric(metric);
        verify(childSink, times(0)).sendMetric(captor.capture());
    }