if err != nil {
				log.Printf("failed to parse end parameter %q: %v", endStr, err)
				return
			}
		}

		c := traceviewer.ViewerDataTraceConsumer(w, start, end)
		if err := generateTrace(parsed, opts, c); err != nil {
			log.Printf("failed to generate trace: %v", err)
		}
	})
}

// traceContext is a wrapper around a traceviewer.Emitter with some additional