### Question:
CommonMetricsFilter implements MeterFilter { public void enableMetric(String metricName) { if (k8sMetricsProperties.isEnableCommonMetricsFilterAction()) { metricName = filter(metricName); if (blacklist.contains(metricName)) { blacklist.remove(metricName); } if (!whitelist.contains(metricName)) { whitelist.add(metricName); } } } CommonMetricsFilter(K8sMetricsProperties k8sMetricsProperties, MetricsProperties properties); MeterFilterReply accept(Meter.Id id); void enableMetric(String metricName); void disableMetric(String metricName); String[] getPrefixes(); void setPrefixes(String[] prefixes); boolean isActionEnabled();  }### Answer:
@Test public void enableMetric() { K8sMetricsProperties k8sMetricsProperties = new K8sMetricsProperties(); k8sMetricsProperties.setEnableCommonMetricsFilter(true); k8sMetricsProperties.setCommonMetricsBlacklist("prefix_abc"); k8sMetricsProperties.setEnableCommonMetricsFilterAction(true); MetricsProperties metricsProperties = new MetricsProperties(); CommonMetricsFilter filter = new CommonMetricsFilter(k8sMetricsProperties, metricsProperties); filter.setPrefixes(new String[]{"prefix"}); MeterFilterReply reply = filter.accept(new Meter.Id("prefix.abc", null, "", "", Meter.Type.COUNTER)); assertEquals(reply, MeterFilterReply.DENY); filter.enableMetric("prefix_abc"); reply = filter.accept(new Meter.Id("prefix.abc", null, "", "", Meter.Type.COUNTER)); assertEquals(reply, MeterFilterReply.NEUTRAL); }