@Initializer
    public static void relocateOldLogs() {
        relocateOldLogs(Jenkins.get().getRootDir());
    }
@Test
    public void testRelocate() throws Exception {
        File d = File.createTempFile("jenkins", "test");
        FilePath dir = new FilePath(d);
        try {
            dir.delete();
            dir.mkdirs();
            dir.child("slave-abc.log").touch(0);
            dir.child("slave-def.log.5").touch(0);

            Computer.relocateOldLogs(d);

            assertEquals(1, dir.list().size()); // asserting later that this one child is the logs/ directory
            assertTrue(dir.child("logs/slaves/abc/slave.log").exists());
            assertTrue(dir.child("logs/slaves/def/slave.log.5").exists());
        } finally {
            dir.deleteRecursive();
        }
    }