### Question:
DefaultTracer implements Tracer { @Override public Span getCurrentSpan() { return TracingContextUtils.getCurrentSpan(); } private  DefaultTracer(); static Tracer getInstance(); @Override Span getCurrentSpan(); @Override Scope withSpan(Span span); @Override Span.Builder spanBuilder(String spanName);  }### Answer:
@Test void defaultGetCurrentSpan() { assertThat(defaultTracer.getCurrentSpan()).isInstanceOf(DefaultSpan.class); }