@Test
  public void testBackupFromMemberWithDiskStore() throws Exception {
    createPersistentRegions(vm0, vm1);

    vm0.invoke(() -> {
      createData(0, 5, "A", regionName1);
      createData(0, 5, "B", regionName2);
    });

    BackupStatus status = vm1.invoke(this::backupMember);
    assertThat(status.getBackedUpDiskStores()).hasSize(2);

    for (DistributedMember key : status.getBackedUpDiskStores().keySet()) {
      assertThat(key).isNotNull();
    }
    assertThat(status.getOfflineDiskStores()).isEmpty();

    validateBackupComplete();

    vm0.invoke(() -> getCache().close());
    vm1.invoke(() -> getCache().close());

    // destroy the current data
    cleanDiskDirsInEveryVM();

    restoreBackup(2);

    createPersistentRegions(vm0, vm1);

    vm0.invoke(() -> {
      validateData(0, 5, "A", regionName1);
      validateData(0, 5, "B", regionName2);
    });
  }
Test of bug 42419.

<p>
TRAC #42419: backed up disk stores map contains null key instead of member; cannot restore
backup files
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/backup/BackupDistributedTest.java