public Builder serviceUrl(String serviceUrl) {
      if (StringUtils.isNullOrEmpty(serviceUrl)) throw new NullPointerException("serviceUrl is null or empty");
      clientProps.put("serviceUrl", serviceUrl);
      return this;
    }
The service URL for the Pulsar client ex. pulsar://my-broker:6650. No default.
zipkin-collector/pulsar/src/main/java/zipkin2/collector/pulsar/PulsarCollector.java