### Question:
TracerShim extends BaseShimObject implements Tracer { @Override public Scope activateSpan(Span span) { return scopeManagerShim.activate(span); } TracerShim(TelemetryInfo telemetryInfo); @Override ScopeManager scopeManager(); @Override Span activeSpan(); @Override Scope activateSpan(Span span); @Override SpanBuilder buildSpan(String operationName); @Override void inject(SpanContext context, Format<C> format, C carrier); @SuppressWarnings("ReturnMissingNullable") @Override SpanContext extract(Format<C> format, C carrier); @Override void close();  }### Answer:
@Test void activateSpan() { Span otSpan = tracerShim.buildSpan("one").start(); io.opentelemetry.trace.Span span = ((SpanShim) otSpan).getSpan(); assertNull(tracerShim.activeSpan()); assertNull(tracerShim.scopeManager().activeSpan()); try (Scope scope = tracerShim.activateSpan(otSpan)) { assertNotNull(tracerShim.activeSpan()); assertNotNull(tracerShim.scopeManager().activeSpan()); assertEquals(span, ((SpanShim) tracerShim.activeSpan()).getSpan()); assertEquals(span, ((SpanShim) tracerShim.scopeManager().activeSpan()).getSpan()); } assertNull(tracerShim.activeSpan()); assertNull(tracerShim.scopeManager().activeSpan()); }