You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: trace_test.go
    path of file: ./repos/cockroach/pkg/util/log
    
    the code of the file until where you have to start completion: // Copyright 2016 The Cockroach Authors.
//
// Use of this so
    
func TestTrace(t *testing.T) {
	ctx := context.Background()

	// Events to context without a trace should be no-ops.
	Event(ctx, "should-not-show-up")

	tracer := tracing.NewTracer()
	sp := tracer.StartSpan("s", tracing.WithRecording(tracingpb.RecordingVerbose))
	ctxWithTrace := tracing.ContextWithSpan(ctx, sp)
	// Events should only go to the trace.
	Event(ctxWithTrace, "test3")
	VEventf(ctxWithTrace, NoLogV(), "test4")
	VErrEventf(ctxWithTrace, NoLogV(), "%s", "test5err")

	rec := sp.FinishAndGetRecording(tracingpb.RecordingVerbose)
	if err := tracing.CheckRecordedSpans(rec, `
		span: s
			tags: _verbose=1
			event: test3
			event: test4
			event: test5err
	`); err != nil {
		t.Fatal(err)
	}
}