code: protected List<ProviderGroup> subscribeFromDirectUrl(String directUrl) {
          List<ProviderGroup> result = new ArrayList<ProviderGroup>();
          List<ProviderInfo> tmpProviderInfoList = new ArrayList<ProviderInfo>();
          String[] providerStrs = StringUtils.splitWithCommaOrSemicolon(directUrl);
          for (String providerStr : providerStrs) {
              ProviderInfo providerInfo = convertToProviderInfo(providerStr);
              if (providerInfo.getStaticAttr(ProviderInfoAttrs.ATTR_SOURCE) == null) {
                  providerInfo.setStaticAttr(ProviderInfoAttrs.ATTR_SOURCE, "direct");
              }
              tmpProviderInfoList.add(providerInfo);
          }
  
          result.add(new ProviderGroup(RpcConstants.ADDRESS_DIRECT_GROUP, tmpProviderInfoList));
          return result;
      }
docs: Subscribe provider list from direct url
  
  @param directUrl direct url of consume config
  @return Provider group list