code: @Override
    public Optional<HttpTracing> build(final Environment environment) {
      if (!isEnabled()) {
        LOGGER.warn("Zipkin tracing is disabled");
        return Optional.empty();
      }
  
      final ReporterMetrics metricsHandler = new DropwizardReporterMetrics(environment.metrics());
  
      final KafkaSender sender =
          KafkaSender.newBuilder()
              .bootstrapServers(bootstrapServers)
              .topic(topic)
              .overrides(overrides)
              .build();
  
      final AsyncReporter<Span> reporter =
          AsyncReporter.builder(sender).metrics(metricsHandler).build();
  
      environment.lifecycle().manage(new ReporterManager(reporter, sender));
  
      LOGGER.info("Sending spans to Kafka topic \"{}\" at: {}", topic, bootstrapServers);
  
      return buildTracing(environment, reporter);
    }
docs: Build a new {@link HttpTracing} instance for interfacing with Zipkin
  
  @param environment Environment
  @return Brave instance