### Question:
SpanBuilderSdk implements Span.Builder { @Override public Span.Builder setParent(Context context) { Objects.requireNonNull(context, "context"); this.isRootSpan = false; this.parent = context; return this; } SpanBuilderSdk(
      String spanName,
      InstrumentationLibraryInfo instrumentationLibraryInfo,
      SpanProcessor spanProcessor,
      TraceConfig traceConfig,
      Resource resource,
      IdsGenerator idsGenerator,
      Clock clock); @Override Span.Builder setParent(Context context); @Override Span.Builder setNoParent(); @Override Span.Builder setSpanKind(Kind spanKind); @Override Span.Builder addLink(SpanContext spanContext); @Override Span.Builder addLink(SpanContext spanContext, Attributes attributes); @Override Span.Builder setAttribute(String key, String value); @Override Span.Builder setAttribute(String key, long value); @Override Span.Builder setAttribute(String key, double value); @Override Span.Builder setAttribute(String key, boolean value); @Override Span.Builder setAttribute(AttributeKey<T> key, T value); @Override Span.Builder setStartTimestamp(long startTimestamp); @Override Span startSpan();  }### Answer:
@Test void setParent_null() { assertThrows( NullPointerException.class, () -> tracerSdk.spanBuilder(SPAN_NAME).setParent(null)); }