public static Sampler create(int tracesPerSecond) {
    if (tracesPerSecond < 0) throw new IllegalArgumentException("tracesPerSecond < 0");
    if (tracesPerSecond == 0) return Sampler.NEVER_SAMPLE;
    return new RateLimitingSampler(Platform.get(), tracesPerSecond);
  }
@Test void zeroMeansDropAllTraces() {
    assertThat(RateLimitingSampler.create(0)).isSameAs(Sampler.NEVER_SAMPLE);
  }