apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/component/PortalSettings.java/PortalSettings/getActiveEnvs
class PortalSettings:  public List<Env> getActiveEnvs() {
    List<Env> activeEnvs = new LinkedList<>();
    for (Env env : allEnvs) {
      if (envStatusMark.get(env)) {
        activeEnvs.add(env);
      }
    }
    return activeEnvs;
  }