### Question:
Samplers { public static Sampler alwaysOff() { return AlwaysOffSampler.INSTANCE; } private  Samplers(); static SamplingResult samplingResult(Decision decision, Attributes attributes); static SamplingResult emptySamplingResult(Decision decision); static Sampler alwaysOn(); static Sampler alwaysOff(); static Sampler parentBased(Sampler root); static ParentBased.Builder parentBasedBuilder(Sampler root); static Sampler traceIdRatioBased(double ratio);  }### Answer:
@Test void alwaysOffSampler() { assertThat( Samplers.alwaysOff() .shouldSample( sampledSpanContext, traceId, SPAN_NAME, SPAN_KIND, Attributes.empty(), Collections.emptyList()) .getDecision()) .isEqualTo(Decision.DROP); assertThat( Samplers.alwaysOff() .shouldSample( notSampledSpanContext, traceId, SPAN_NAME, SPAN_KIND, Attributes.empty(), Collections.emptyList()) .getDecision()) .isEqualTo(Decision.DROP); assertThat( Samplers.alwaysOff() .shouldSample( null, traceId, SPAN_NAME, SPAN_KIND, Attributes.empty(), Collections.emptyList()) .getDecision()) .isEqualTo(Decision.DROP); }
@Test void alwaysOffSampler_GetDescription() { assertThat(Samplers.alwaysOff().getDescription()).isEqualTo("AlwaysOffSampler"); }