apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/spi/defaultimpl/DefaultUserService.java/DefaultUserService/findByUserIds
class DefaultUserService:  @Override
  public List<UserInfo> findByUserIds(List<String> userIds) {
    if (userIds.contains("apollo")) {
      return Lists.newArrayList(assembleDefaultUser());
    }
    return null;
  }