public Map<String, MetaProperties> logDirProps() {
        return logDirProps;
    }
@Test
    public void testCopierGenerateValidDirectoryId() {
        MetaPropertiesMockRandom random = new MetaPropertiesMockRandom();
        MetaPropertiesEnsemble.Copier copier = new MetaPropertiesEnsemble.Copier(EMPTY);
        copier.setRandom(random);
        copier.logDirProps().put("/tmp/dir1",
            new MetaProperties.Builder().
                setVersion(MetaPropertiesVersion.V1).
                setClusterId("PpYMbsoRQV-589isZzNzEw").
                setNodeId(0).
                setDirectoryId(new Uuid(2336837413447398698L, 1758400403264101670L)).
                build());
        copier.logDirProps().put("/tmp/dir2",
            new MetaProperties.Builder().
                setVersion(MetaPropertiesVersion.V1).
                setClusterId("PpYMbsoRQV-589isZzNzEw").
                setNodeId(0).
                setDirectoryId(new Uuid(4341931186263415792L, 6389410885970711333L)).
                build());
        // Verify that we ignore the non-safe IDs, or the IDs that have already been used,
        // when invoking generateValidDirectoryId.
        assertEquals(new Uuid(7265008559332826740L, 3478747443029687715L),
            copier.generateValidDirectoryId());
    }