apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/ReleaseService.java/ReleaseService/findReleaseById
class ReleaseService:  public ReleaseDTO findReleaseById(Env env, long releaseId) {
    Set<Long> releaseIds = new HashSet<>(1);
    releaseIds.add(releaseId);
    List<ReleaseDTO> releases = findReleaseByIds(env, releaseIds);
    if (CollectionUtils.isEmpty(releases)) {
      return null;
    }
    return releases.get(0);

  }