docs: private Configuration retrieveConfig(NestedConfigHelper configHelper, ConfigurationAdmin configAdmin) throws InitWithoutConfig {
          if (configHelper == null)
              throw new InitWithoutConfig("Configuration not found");
          // We need configAdmin to list the configurations of nested classloader elements with this application as their parent
          if (configAdmin == null)
              throw new InitWithoutConfig("ConfigurationAdmin service not found");
  
          String parentPid = (String) configHelper.get(Constants.SERVICE_PID);
          String sourcePid = (String) configHelper.get("ibm.extends.source.pid");
          if (sourcePid != null) {
              parentPid = sourcePid;
          }
          try {
              StringBuilder filter = new StringBuilder();
              filter.append("(&");
              filter.append(FilterUtils.createPropertyFilter("service.factoryPid", "com.ibm.ws.classloading.classloader"));
              filter.append(FilterUtils.createPropertyFilter("config.parentPID", parentPid));
              filter.append(")");
              Configuration[] configs = configAdmin.listConfigurations(filter.toString());
              if (configs == null || configs.length != 1) {
                  throw new InitWithoutConfig("No classloader element found");
              }
              Configuration config = configs[0];
              if (config.getProperties() == null) {
                  if (tc.isErrorEnabled())
                      Tr.error(tc, "cls.classloader.missing", config.getPid());
                  config.delete();
                  throw new InitWithoutConfig("Classloader config not found");
              }
              return config;
          } catch (IOException e) {
              throw new InitWithoutConfig("Configuration for classloader not found, exception " + e);
          } catch (InvalidSyntaxException e) {
              throw new InitWithoutConfig("Configuration for classloader not found, exception " + e);
          }
      }