PollIgnoresFileAlreadySeen

    @Test
    public void pollIgnoresFileAlreadySeen() throws Exception {
        final CountDownLatch stopLatch = new CountDownLatch(1);
        filePollingChannel.addInterceptor(new ChannelInterceptor() {
            @Override
            public void postSend(Message<?> message, MessageChannel channel, boolean sent) {
                stopLatch.countDown();
            }
        });
        copy(TestUtils.locateClasspathResource(TestUtils.FILE_FIXTURE_PATH), new File(inboundReadDirectory, TestUtils.FILE_FIXTURE_NAME ));
        //wait for stopLatch before asserting
        assertThat(stopLatch.await(5, TimeUnit.SECONDS), is(true));
        assertThatDirectoryHasFiles(inboundProcessedDirectory, 1);
        assertThatDirectoryHasFiles(inboundOutDirectory, 1);
        assertThatDirectoryIsEmpty(inboundReadDirectory);
        assertThatDirectoryIsEmpty(inboundFailedDirectory);
        copy(TestUtils.locateClasspathResource(TestUtils.FILE_FIXTURE_PATH), new File(inboundReadDirectory, TestUtils.FILE_FIXTURE_NAME ));
        Thread.sleep(2000); //wait longer than the polling period
        assertThatDirectoryIsEmpty(inboundFailedDirectory);
        assertThatDirectoryHasFiles(inboundReadDirectory, 1);
        assertThatDirectoryHasFiles(inboundProcessedDirectory, 1);
        assertThatDirectoryHasFiles(inboundOutDirectory, 1);
    }