code: private static StringBuilder displayServiceProperties(ServiceReference reference) {
  
          StringBuilder sb = new StringBuilder();
  
          for (String propertyKey : reference.getPropertyKeys()) {
              sb.append(String.format("%s = %s%n", propertyKey, reference.getProperty(propertyKey)));
          }
          if (reference.getPropertyKeys().length == 0) {
              sb.append("EMPTY");
          }
  
          return sb;
      }
docs: ---------------- UTILS DISPLAY