### Question:
DefaultDistributionSummary implements DistributionSummary { @Override public void record(long amount) { if (amount >= 0) { totalAmount.addAndGet(amount); count.incrementAndGet(); } } DefaultDistributionSummary(Clock clock, Id id); @Override Id id(); @Override boolean hasExpired(); @Override void record(long amount); @Override Iterable<Measurement> measure(); @Override long count(); @Override long totalAmount();  }### Answer:
@Test public void testRecord() { DistributionSummary t = new DefaultDistributionSummary(clock, NoopId.INSTANCE); t.record(42); Assertions.assertEquals(t.count(), 1L); Assertions.assertEquals(t.totalAmount(), 42L); }