List spans = [new StyledTextOutputEvent.Span(StyledTextOutput.Style.UserInput, 'UserInput'),
                new StyledTextOutputEvent.Span(StyledTextOutput.Style.Normal, 'Normal'),
                new StyledTextOutputEvent.Span(StyledTextOutput.Style.Header, 'Header')
        ]
        def event = new StyledTextOutputEvent(100, 'category', LogLevel.LIFECYCLE, null, spans)

        when:
        event.render(output)

//   can free a whole span if none of the objects are marked, but that
//   isn't its goal. This can be driven either synchronously by
//   mcentral.cacheSpan for mcentral spans, or asynchronously by
//   sweepone, which looks at all the mcentral lists.
//
// * The span reclaimer looks for spans that contain no marked objects
//   and frees whole spans. This is a separate algorithm because

			scopes.Framework.Debugf("cannot parse or cannot find spans in trace object %+v", t)
			continue
		}
		var spans []Span
		for _, obj := range spanObjs {
			newSpan := buildSpan(obj)
			spans = append(spans, newSpan)
		}
		for p := range spans {
			for c := range spans {
				if spans[c].ParentSpanID == spans[p].SpanID {
					spans[p].ChildSpans = append(spans[p].ChildSpans, &spans[c])
				}
			}

// TODO(bianpengyuan) consider using zipkin proto api https://github.com/istio/istio/issues/13926
type Span struct {
	SpanID       string
	ParentSpanID string
	ServiceName  string
	Name         string
	ChildSpans   []*Span
}

// Trace represents a trace by a collection of spans which all belong to that trace
type Trace struct {
	Spans []Span
}

// New returns a new instance of zipkin.

issue:
  - 28801

releaseNotes:
- |
  **Added** canonical service tags to Envoy-generated trace spans.
upgradeNotes:
  - title: Service Tags added to trace spans
    content: |
      Istio now configures Envoy to include tags identifying the canonical service for a workload in generated trace spans.

      This will lead to a small increase in storage per span for tracing backends.

        OperationIdentifier buildOperationId = decoder.readBoolean() ? new OperationIdentifier(decoder.readSmallLong()) : null;
        List<StyledTextOutputEvent.Span> spans = spanSerializer.read(decoder);
        return new StyledTextOutputEvent(timestamp, category, logLevel, buildOperationId, spans);
    }

	// this block. This number is used to help determine when a block
	// may be safely recycled.
	popped atomic.Uint32

	// spans is the set of spans in this block.
	spans [spanSetBlockEntries]atomicMSpanPointer
}

// push adds span s to buffer b. push is safe to call concurrently
// with other push and pop operations.
func (b *spanSet) push(s *mspan) {
	// Obtain our slot.

import java.util.List;

/**
 * A label where its text can be styled.
 */
public interface StyledLabel extends Label {
    void setText(List<StyledTextOutputEvent.Span> spans);
    void setText(StyledTextOutputEvent.Span span);

        }

        private StyledTextOutputEvent styledTextEvent(long timestamp, StyledTextOutputEvent.Span... spans) {
            return new StyledTextOutputEvent(timestamp, category, LogLevel.LIFECYCLE, buildOperationIdentifier, Arrays.asList(spans));
        }

        private void doOutput(RenderableOutputEvent event) {

		c = pp.mcache
	}
	return c
}

// refill acquires a new span of span class spc for c. This span will
// have at least one free object. The current span in c must be full.
//
// Must run in a non-preemptible context since otherwise the owner of
// c could change.
func (c *mcache) refill(spc spanClass) {
	// Return the current cached span to the central lists.
	s := c.alloc[spc]

	if s.allocCount != s.nelems {