### Question:
TracerSdk implements Tracer { @Override public Span getCurrentSpan() { return TracingContextUtils.getCurrentSpan(); } TracerSdk(TracerSharedState sharedState, InstrumentationLibraryInfo instrumentationLibraryInfo); @Override Span getCurrentSpan(); @Override Scope withSpan(Span span); @Override Span.Builder spanBuilder(String spanName);  }### Answer:
@Test void defaultGetCurrentSpan() { assertThat(tracer.getCurrentSpan()).isInstanceOf(DefaultSpan.class); }
@Test void getCurrentSpan() { assertThat(tracer.getCurrentSpan()).isInstanceOf(DefaultSpan.class); try (Scope ignored = TracingContextUtils.withSpan(span, Context.current()).makeCurrent()) { assertThat(tracer.getCurrentSpan()).isSameAs(span); } assertThat(tracer.getCurrentSpan()).isInstanceOf(DefaultSpan.class); }