@Test
  public void testPutWithTTL() throws Exception {
    createTable(TestPutWithTTLCoprocessor.class.getName());

    try (Table t = util.getConnection().getTable(tableName)) {
      t.put(new Put(row1).addColumn(test, dummy, dummy).setTTL(3000));
      assertRowCount(t, 2);
      // wait long enough for the TTL to expire
      Thread.sleep(5000);
      assertRowCount(t, 0);
    }
  }
Tests that added mutations from coprocessors end up in the WAL.
hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestRegionObserverForAddingMutationsFromCoprocessors.java