@Override
    public void postCompletedDeleteTableAction(
      final ObserverContext<MasterCoprocessorEnvironment> ctx, final TableName tableName)
      throws IOException {
      // the AccessController test, some times calls only and directly the
      // postCompletedDeleteTableAction()
      if (tableDeletionLatch != null) {
        tableDeletionLatch.countDown();
      }
    }
Test that use this should have a timeout, because this method could potentially wait forever.
hbase-server/src/test/java/org/apache/hadoop/hbase/util/BaseTestHBaseFsck.java