Tracer { public Span newTrace() { return _toSpan(null, newRootContext(0)); } Tracer(
    Clock clock,
    Propagation.Factory propagationFactory,
    SpanHandler spanHandler,
    PendingSpans pendingSpans,
    Sampler sampler,
    CurrentTraceContext currentTraceContext,
    boolean traceId128Bit,
    boolean supportsJoin,
    boolean alwaysSampleLocal,
    AtomicBoolean noop
  ); @Deprecated Tracer withSampler(Sampler sampler); Span newTrace(); final Span joinSpan(TraceContext context); Span newChild(TraceContext parent); Span nextSpan(TraceContextOrSamplingFlags extracted); Span toSpan(TraceContext context); SpanInScope withSpanInScope(@Nullable Span span); SpanCustomizer currentSpanCustomizer(); @Nullable Span currentSpan(); Span nextSpan(); ScopedSpan startScopedSpan(String name); ScopedSpan startScopedSpan(String name, SamplerFunction<T> samplerFunction, T arg); Span nextSpan(SamplerFunction<T> samplerFunction, T arg); Span nextSpanWithParent(SamplerFunction<T> samplerFunction, T arg,
    @Nullable TraceContext parent); ScopedSpan startScopedSpanWithParent(String name, @Nullable TraceContext parent); @Override String toString();  }
@Test public void newTrace_isRootSpan() { assertThat(tracer.newTrace()) .satisfies(s -> assertThat(s.context().parentId()).isNull()) .isInstanceOf(RealSpan.class); }
@Test public void useSpanAfterFinished_doesNotCauseBraveFlush() { simulateInProcessPropagation(tracer, tracer); GarbageCollectors.blockOnGC(); tracer.newTrace().start().abandon(); assertThat(spans).hasSize(1); assertThat(spans.get(0).annotations()) .extracting(Map.Entry::getValue) .doesNotContain("brave.flush"); }
@Test public void newTrace_resultantSpanIsLocalRoot() { Span span = tracer.newTrace(); assertThat(span.context().spanId()).isEqualTo(span.context().localRootId()); assertThat(span.context().isLocalRoot()).isTrue(); }