private void createDiskStore(final String diskStoreName, final File diskDir) {
    DiskStoreFactory diskStoreFactory = getCache().createDiskStoreFactory();
    diskStoreFactory.setDiskDirs(new File[] {diskDir});
    diskStoreFactory.create(diskStoreName);
  }
Successful if a member performs a full backup when its backup data is not present in the
performBackupBaseline (for whatever reason). This also tests what happens when a member is
offline during the performBackupBaseline backup.

<p>
The test is regarded as successful when all of the missing members oplog files are backed up
during an performBackupIncremental backup. This means that the member performed a full backup
because its oplogs were missing in the performBackupBaseline.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/backup/IncrementalBackupDistributedTest.java