Tracer { @Deprecated public Tracer withSampler(Sampler sampler) { if (sampler == null) throw new NullPointerException("sampler == null"); return new Tracer( clock, propagationFactory, spanHandler, pendingSpans, sampler, currentTraceContext, traceId128Bit, supportsJoin, alwaysSampleLocal, noop ); } 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 withSampler() { Sampler sampler = new Sampler() { @Override public boolean isSampled(long traceId) { return false; } }; tracer = tracer.withSampler(sampler); assertThat(tracer.sampler) .isSameAs(sampler); }