@Test
  public void testTargetOfSplitAndMerge() throws Exception {
    final TableName tn = TableName.valueOf(name.getMethodName());
    try {
      final int tnRegionCount = createTableTargetOfSplitAndMerge(tn);
      assertFalse(admin.normalizerSwitch(true).get());
      assertTrue(admin.normalize().get());
      TEST_UTIL.waitFor(TimeUnit.MINUTES.toMillis(5),
        new MatcherPredicate<>("expected " + tn + " to split or merge (probably split)",
          () -> getRegionCountUnchecked(tn), not(comparesEqualTo(tnRegionCount))));
    } finally {
      dropIfExists(tn);
    }
  }
A test for when a region is the target of both a split and a merge plan. Does not define
expected behavior, only that some change is applied to the table.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/normalizer/TestSimpleRegionNormalizerOnCluster.java