### Question:
MicrometerHistogram implements Histogram { @Override public void update(long value) { summary.record(value); } MicrometerHistogram(DistributionSummary summary); @Override void update(long value);  }### Answer:
@Test public void testUpdate() { assertEquals(0, summary.count()); histogramWrapper.update(100); assertEquals(1, summary.count()); assertEquals(100, summary.takeSnapshot().total(), 0.0); }