@Test
  public void testSplitDeletedRegion() throws IOException {
    REGIONS.clear();
    String region = "region_that_splits";
    REGIONS.add(region);

    generateWALs(1);
    useDifferentDFSClient();

    Path regiondir = new Path(TABLEDIR, region);
    fs.delete(regiondir, true);
    WALSplitter.split(HBASELOGDIR, WALDIR, OLDLOGDIR, fs, conf, wals);
    assertFalse(fs.exists(regiondir));
  }
@return set of wal names present prior to split attempt.
@throws IOException if the split process fails
hbase-server/src/test/java/org/apache/hadoop/hbase/wal/TestWALSplit.java