code: public ConnectionDecoratorFactory resolve() {
          int loadingIndex = Integer.MIN_VALUE;
          ConnectionDecoratorFactory connectionDecoratorFactory = null;
          Iterator<ConnectionDecoratorFactoryService> connectionDecoratorFactoryServiceIterator = serviceLoader.iterator();
          while (connectionDecoratorFactoryServiceIterator.hasNext()) {
              try {
                  ConnectionDecoratorFactoryService connectionDecoratorFactoryService = connectionDecoratorFactoryServiceIterator.next();
                  int currentLoadingIndex = connectionDecoratorFactoryService.loadingIndex();
                  if (currentLoadingIndex > loadingIndex) {
                      ConnectionDecoratorFactory currentConnectionDecoratorFactory = connectionDecoratorFactoryService.load();
                      if (currentConnectionDecoratorFactory != null) {
                          connectionDecoratorFactory = currentConnectionDecoratorFactory;
                          loadingIndex = currentLoadingIndex;
                      }
                  }
              } catch (LinkageError e) {
                  LOGGER.info("Couldn't load ConnectionDecoratorFactoryService on the current JVM", e);
              }
          }
          if (connectionDecoratorFactory != null) {
              return connectionDecoratorFactory;
          }
          throw new IllegalStateException("No ConnectionDecoratorFactory could be loaded!");
      }
docs: Resolve ConnectionDecoratorFactory from the Service Provider Interface configuration
  
  @return ConnectionDecoratorFactory