}
            }
        }
    }

    /**
     * Test that setSearcher and register can be called concurrently.
     */
    @Test
    public void test_concurrentSetAndRegister() throws Exception {
        final int numIterations = 100;
        final CountDownLatch startLatch = new CountDownLatch(1);
        final CountDownLatch endLatch = new CountDownLatch(2);