private void waitForBackup() {
    Collection<DiskStore> backupInProgress = getCache().listDiskStores();
    Collection<DiskStoreImpl> backupCompleteList = new ArrayList<>();

    while (backupCompleteList.size() < backupInProgress.size()) {
      for (DiskStore diskStore : backupInProgress) {
        if (((DiskStoreImpl) diskStore).getInProgressBackup() == null
            && !backupCompleteList.contains(diskStore)) {
          backupCompleteList.add((DiskStoreImpl) diskStore);
        }
      }
    }
  }
Verifies that a user deployed jar file is included as part of the backup.
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/backup/IncrementalBackupIntegrationTest.java