apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/AdditionalUserInfoEnrichServiceImpl.java/AdditionalUserInfoEnrichServiceImpl/extractOperatorId
class AdditionalUserInfoEnrichServiceImpl:  private <T> Set<String> extractOperatorId(List<UserInfoEnrichedAdapter> adapterList) {
    Set<String> operatorIdSet = new HashSet<>();
    for (UserInfoEnrichedAdapter adapter : adapterList) {
      if (StringUtils.hasText(adapter.getFirstUserId())) {
        operatorIdSet.add(adapter.getFirstUserId());
      }
      if (StringUtils.hasText(adapter.getSecondUserId())) {
        operatorIdSet.add(adapter.getSecondUserId());
      }
      if (StringUtils.hasText(adapter.getThirdUserId())) {
        operatorIdSet.add(adapter.getThirdUserId());
      }
    }
    return operatorIdSet;
  }