Tracer { public <T> Span nextSpanWithParent(SamplerFunction<T> samplerFunction, T arg, @Nullable TraceContext parent) { return _toSpan(parent, nextContext(samplerFunction, arg, parent)); } 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 nextSpanWithParent() { Span span = tracer.nextSpanWithParent(deferDecision(), false, context); assertThat(span.context().parentId()).isEqualTo(context.spanId()); }
@Test public void nextSpanWithParent_overrideToMakeNewTrace() { Span span; try (Scope ws = currentTraceContext.newScope(context)) { span = tracer.nextSpanWithParent(deferDecision(), false, null); } assertThat(span.context().parentId()).isNull(); }