private void initApplicationsToCleanup() {
    if (this.applicationsToCleanup != null) {
      return;
    }
    NodeHeartbeatResponseProtoOrBuilder p = viaProto ? proto : builder;
    List<ApplicationIdProto> list = p.getApplicationsToCleanupList();
    this.applicationsToCleanup = new ArrayList<ApplicationId>();

    for (ApplicationIdProto c : list) {
      this.applicationsToCleanup.add(convertFromProtoFormat(c));
    }
  }