@Test
public void testOctalFileMode644() {

    Set<PosixFilePermission> perms = createPermissionSet(PosixFilePermission.OWNER_READ,
            PosixFilePermission.OWNER_WRITE, PosixFilePermission.GROUP_READ, PosixFilePermission.OTHERS_READ);
    Assert.assertEquals(0644, FilePermissionHelper.toOctalFileMode(perms));
}