@Test
public void disposeUnused() throws Exception {

    final Journal journal = context.mock(Journal.class);
    DataFileAccessorPool underTest = new DataFileAccessorPool(journal);
    context.checking(new Expectations(){{exactly(1).of(journal).getInflightWrites();}});
    DataFile dataFile = new DataFile(new File(temporaryFolder.getRoot(), "aa"), 1);
    underTest.closeDataFileAccessor(underTest.openDataFileAccessor(dataFile));
    assertEquals("one in the pool", 1, underTest.size());
    underTest.disposeUnused();
    assertEquals("0 in the pool", 0, underTest.size());
    context.assertIsSatisfied();
}